Hi C.. It took me a couple days to think on this.
I have seen mother's love their children differently. It is heartbreaking. My friend in college mother only showed affection and adoration to the middle daughter who was the pretty child of the three girls. The eldest took many years to get her life together and now does better that she has found a good man and a beautiful family of her own.
My very own wonderful sister treated her children differently and if it weren't for her wonderful husband who adored each child the same, things may have been different.
Another one of my friend's daughter in laws treated her eldest child so differently that we too had debated on calling CPS. It was so abusive and we were not sure what to do. SOme of the stories would bring tears to your eyes.
I intercepted on a couple of occasions even though I am not family and the daughter in law will not speak to me or even come over if she knows I am there. The family has fought with the husband to take action and it divided their family. He believed his wife. We believed what we saw when he was not there.
CPS is pretty serious and the children will be removed from the home. She will probably never speak to you again and than your influence will be lost.
Did something happen to her? I would think that maybe something has. Maybe her husband did something and the boy reminds her of him or something happened when she was younger that she might not recall and it comes out on the first born. I agree, postpartum depression too will be most horrible if you have it.
Can I ask that you speak with her letting her know what you see and you love her so much and you are worried, what can you do? Can she go to counseling and you will watch the kids? Will she go to the doctor and talk with him about her home life and you will watch the kids?
She will not heal on her own. Please take this all very seriously. Women that are suffering sometimes can do terrible things to their children.
If she is just a messy person or too lazy to dress her kids or bathe them - some people are that way too - than you have to bite your tongue and maybe clean while you visit. If she loves them haphazardly but they are safe and cared for, then you have to do what I think you have already decided to do - be patient. If she is neglectful because she lacks the energy or desire, maybe a large family was not what she needed and she needs your support. Could you take the boy or two over to your house some days?
It all comes down to the children. Life will be harder for the eldest and especially since he is singled out. It will affect his self esteem and who he becomes. She may be actually reaching out for help and the child is the closest she has and when he fails because he is a child, she lashes out to him.
I would like to recommend that you speak to a professional about this and get a real opinion on how to help her. You are so wonderful to be so concerned and so loving to her. Makes me wish you were my sister too.
God bless the children, C.