Of course your baby is getting used to your sister in law. She is becoming the "mommy" figure in his life, because she is with him more than you are. I mean, how weird does that feel to say, "when I have him, even on the weekends?" You sound like the babysitter. Your instincts are right on. You have justified guilt for not being home with your newborn. I think you have way too much on your plate. When your son starts school, you will have the whole day to work and/or work on your Master's. I'm here to tell you, 6 years goes by in a flash! I suggest you make a plan to be home. That means looking at the budget and figuring out what you can live without, like cell phones, cable, expensive clothes, etc. Try your hardest to make it all work on your husband's income. If that isn't possible, work part time at night while your baby is sleeping to make up for a little lost income. Go to your husband, tell him how much you want to be the mommy of your son, and how you know he is man enough to take care of you all. Unless you both were raised by feministas this is the natural way to feel, and your husband will be proud that you have created a budget, and a way to take care of your son and your home so that your husband will have a loving environment to come home to. Most women these days think this is June Cleaver mentality(only exists on old tv shows)and won't work. However, I have been living this life for 7 years now. It isn't because I am lucky and have a husband who makes loads of money. No, it's because we made the choice that I would be the one staying home and taking care of our kids. I wasn't going to give that job to anyone else to do for me. We planned like crazy when I was pregnant, and of course we were a little scared when we looked at diaper prices, but we made it work through 2 kids. Quick story, I just recently started working full time at night as a Caregiver for elderly at an assisted living home. I have only been working for about a month, and my husband came to me and asked me to quit my job. He sees how tired I am, and doesn't want the kids to miss out on having fun with Mom this Summer. We know my husband will be laid off at the end of the year, so I was trying to earn a little money to stick in the bank, you know, to help our family. Come to find out, my family needs ME more than we need a PAYCHECK right now. You have no idea how proud of my husband I am for thinking this way. I am also proud of myself for creating my footprint as a mom my kids want to hang with all Summer. When I told my 7 yr old son that after 5 more nights of working, I will have the whole Summer off, he jumped up and down screaming, "YAY." When I asked him why he is so happy, he said, "because, then we can actually be with you." My heart melted and I knew it was the right decision. I worked when they were sleeping, but they knew I was gone. I guess it bothered them to know I wasn't in the bedroom next door. I also had to take a couple hours of nap time after my husband got home from work, before I had to go to work. So, I missed time with my husband and kids, and they felt it. So, I can always go back to work when school starts. My point is, don't underestimate the importance of you to your son, husband and home. Good luck and follow your instincts. We have them for a reason.