I'm surprised at the comments. Honestly girl, just because someone is a woman, doesnt mean she is going to be nice. I would make every effort to have a relationship with my sil and to make aure that the kids are bonded but 🤷♀️
Its sad that she doesnt want a relationship with you, she sounds like a nasty person, especially leaving you at their home on xmas day and then not getting in touch when you were dealing with your baby losses 💐
Just because you and your brother grew up together doesnt mean that you will always have a relationship and it sounds like your brother has chosen his wife.
Are you quite a kind sweet person? Your brother doesnt like women like that, it sounds.
Its time to get tough op. Kindly, stop moping about your sil. Stop hoping for her to treat you like a sister, it isnt going to happen.
You have some work to do on yourself imo. No judgement as so do i! But you can't be so down about this. Time to move on and enjoy your life with dd.
Don't buy any presents or reach out at all. And if she asks why, tell her. Say you make zero effort so i'm not going to. Then leave it at that, don't bring it up again.
Your sil might make the perfunctory phone calls to make it look like she isnt in the wrong, but stand firm and focus on being happy with dd.
Do you have a man? What do you do with your dd? There's more to life than cousins! xx