Unsupportive Family

So my SIL is here for a week and we spoke about my miscarriage when she got here. She was extremely unsupportive about it and told me that it wasn’t a child it was just a sack of cells and it wasn’t a part of me or my significant other. She told me that the child didn’t have a heart or heartbeat so there was no child at all. I was 6 weeks along when we miscarried. She told me that she let my significant other know that the tattoo he got in honor of our child was stupid and our child didn’t deserve that tattoo and it was only meant for parents who had an actual loss of their child. I haven’t told my significant other because I didn’t want to cause any issues between them, but it’s affecting our relationship. I’m trying to make jokes and laugh to try to hide the pain and they’ve been at his expense. I’m not really sure what I’m trying to get out of posting this, I just don’t know where else to turn. My worst fears came true, our families won’t even recognize our child as a child and a human.