I am wondering, did she have some psychological issues after giving birth? My friend had and ended up needing professional help, due to severe depressions, during which she could not touch her son or her husband, as it was repulsive to her. It took a lot of time for it to go back to normal, thanks to professional help, and medication. Not all women have it this severe, but they may have a milder form. If not treated, it can go on and on and on and can last for few years.
Also some women after having kids do forget that before they had them, they were partners, lovers, wives, and they just focus on being mother and everything else goes away. Unfortunately, the women have to realize that they are doing this. Good communication is the key here. However, if you write her a letter or email, saying how you feel, and she just turns that down completely, then you do have a problem. As she will likely not feel like there is something to be sorted and that you just have to understand that things are like this now.
My colleague was in this situation, so the result was, he divorced his wife when the kid was less than 5 years old. She did not allow him to hug her, kiss her, cuddle her. She just barked at him even in public, she made it clear he is the wrong one and she is the saint, so he divorced her and now have new family and is much happier. Not saying that divorce is the solution, but sometimes it can be. And unfortunately, the women often do bring this on themselves. I am saying this as a woman.
And as someone, whose now ex-friend, admited, that she only has sex to have kids with her husband, but she always hidden how much she hates having sex, but does a good job so he thinks she enjoys it. I do not dare to think what will happen after she has the kids... I guess the husband will be in the same situation. No sex, no cuddless, no hugs, no kisses.
The advice not to push for sex and help at home is nice, and definitely worth mentioning, but lot of guys already do help at home, including cleaning dust, laundry, or shopping. If you already do that, then I am afraid that the issue is partly on her side and unless she decides to sort it, you will not be able to do much. Regardless how nice you treat her or how you spoil her and help her.