If possible forget your mother-in-law. Be cordial, include her when appropriate in activities. Stop judging your actions by how she does hers. She is important as the mother of your husband and grandmother to your baby but not as an arbitor of what is right or wrong or even how well it's done.
The only person you need to include as you decide on family values and build family traditions is your husband. Yes, he'll want to continue with some things from his growing up years and so will you. The two of you decide how to meld them together for your little family.
If your mother-in-law is copying you it may not be to show you up. She may just want to be young again. When she sees you and your friends having fun she may be trying to make fun for herself and her friends.
How do you know she does it better? If you are going to her parties I suggest that you stop. And you needn't invite her to yours unless you're inviting other family members of her generation.
It took me awhile to realize that both my daughter and I needed to decide on boundaries between ourselves and to talk about them in clear ways. I was babysitting everyday in her home as well as providing some financial assistance. That made respecting boundaries more difficult.
The one boundary that has been the most helpful for me is that I do not give advice unless she asks me to. I also decided what I was willing to do to help and be strong enough to say no when I wanted to.
Here are examples from a mother's view. My daughter seems to need to talk and talk about anything that she is having difficulty with. I'm a problem solver and I was trying to help her make decisions. I didn't tell her what to do but it felt like that to her. Now I just sympathetically listen mostly with me presence. I don't make any sort of comments as she goes along. Not even, I understand, so that she would move on. If I have something else planned or am not feeling well I tell her that and suggest we talk another time. She is usually disappointed and I can sense that in her voice. At first I would try to "talk" her out of her disappointment. By explaining more about what I was doing, reminding her that I was just at her place and would be back again tomorrow if she'd like. By expressing sympathy that I couldn't talk or if I knew what the problem was about saying I knew is was important to talk and sometimes but more rarely as time went on.
A big "boundary" that she set for me is that I do her housework while I was babysitting. She was always unhapppy with me about the housework when she got home. For several months I tried to figure out what she actually wanted me to do and what should the apt look like when she got home. I felt that nothing I did housework wise was good enough and I told her she had a choice. Accept what I was able to do or get a different babysitter. She put her daughter in preschool and her son in daycare. She had to pay for both. She wasn't paying me. We were both much happier. I visited often and continued to babysit short term but she didn't see me as responsible for her house. We had both bought into the idea that housework was my responsibility since I was there all day. I think her being critical was her way of being separate from me. An artificial boundary.
The two of us talked about boundaries and explained our own boundary to the other. A part of that talk was each of us saying what we wanted to happen. I wanted to be there for my daughter and she said she wanted me to just listen and not give advice unless she asked. I agreed but it did take me several weeks to get into the flow.
The issue that I wanted a boundary for was my taking care of her housework. Eventually we agreed that I would watch the kids only when I was able and wanted to and compromised by agreeing that I would have the toys picked up and put away be the time she came home.
We've been practicing this for several months and I'm feeling comfortable with it. I think my daughter is for the most part, though she would like me to help more with housework. :):):)
Your boundary issues sound to be different than my daughter's and mine but I wrote about our experience so that you could have a model and explaination of boundaries.
If your mother-in-law won't co-operate in deciding upon boundaries you and your husband decide on the boundaries to be kept in your house. An example would be we can only have you visit once a week. And give the reason such as we're trying to build a life for ourselves. We don't want to totally exclude you but we need more time to ourselves while we do this. And the boundary of not giving advice unless asked for will help you too. This is a boundary that all parents have difficulty with.
And you work on not comparing what you do with what your mother-in-law does. As you said she's had more experience. By the time you reach her age maybe you'll do better. But my philosophy of life is that when I'm doing something I'm doing it for my own pleasure. It doesn't have to be perfect. I count it a success if I'm pleased with it. And if it's a party, such as your girls night out get together, if people had a good time.
My mother had a saying ever since I can remember. There are 10 and 20 ways to write a treble a. A treble a is a sign in music. She told me that there is rarely only 1 right way to do something. And she followed that maxim with me. When she visited she would defrost my refrigerator. When I bragged on her doing that others said they would not like their mother to do that.
Last remark there are many ways to be a mother to an adult or a mother-in-law. Your relationship is built by the two of you talking about what you want and then deciding on how much you can give. You start by listing your wishes before having a discussion. Decide on some that you will not give on but have other's on which you can be flexible. If she won't co-operate in doing that then you write down the rules and if she doesn't follow them there has to be a consequence. For my daughter and me, if there is tension, we leave the other's house before an argument develops and sometimes remain distant from each other for a few days. We can ask the other to leave if they don't leave on their own. Other times we remind the other of the boundary and the other says, "oh, I forget!" and frequently laugh together. The key to all this is respect of each other's boundaries.
I hope that you can work out a comfortable role with your mother-in-law. It will take time and patience. If she doesn't want to cooperate it will take you time to learn how to enforce the boundary without anger. But anger is OK at the start.
I just realized that it's possible that you live with your mother-in-law. If so your are still dealing with boundaries but in a much more complicated situation. The best thing to do is to get your own place no matter how modest. It may be possible to get help with housing as well as food stamps, health care, and job training.
You have to be on your own to qualify so if you apply say that you want to move out and need helping doing so. Give your mother-in-laws address as a temporary one.
If you live in her home, it's important to have a room that is yours and into which she cannot come. You can enforce the boundary of not giving advice by walking away and going to your room. You'll need your husband's help especially in this case. He has to back you up.
He has to back you up if you're in your own home but living with his mother will make it much more difficult for him.