Yesterday we lost my MIL to be after a very short illness. We knew she wouldn't survive long after her diagnosis but we thought she would be able to come home. She is my fiancees mum so not my official MIL but I referred to her as that and she referred to me as her daughter in law. She knew I loved her and she loved me. 
 

I sat with her in the hospital the night she passed, holding her hand, which was so peaceful and calming and I think she knew I was there (her children weren't there). Unfortunately some of her children and their partners really haven't accepted me into their family (nobody knows why) and hated the fact I was there. When they arrived I was told to get out of the way (which I was happy to do) but the comment hurt and made me feel completely useless. I feel like I shouldn't be sad as she wasn't my mum but honestly I'm gutted. She won't get to be at our wedding, I won't get to sit with her and chat about everything, she won't get to hold our babies.

I'm doing my best to help my fiancée and FIL. 

Has anyone had any experience of this situation? I feel like I can't grieve and that I shouldn't be around, although fiancée and FIL say I should. I'm worried about being upset, as I don't want to make other people upset. I don't want to make things worse with the family, although I do know I haven't actually done anything wrong. I guess I'm just not sure what to do in this situation.