I'm so sorry OP, I hope you get good news on Friday.
A relative has done this to me.
We lost a baby to stillbirth at the end of our second trimester. Because I wasn't full term, lots of people didn't think our baby was real.
This particular relative told me she knew exactly how I felt, as she had a small bleed a few days before DS was born and thought it meant he would be born with a missing finger or something.
Three days after I gave birth to our stillborn son, she asked me if it still hurts to give birth if the baby is already dead.
She discussed what was ''wrong" with me with total strangers and then told the family their opinion on me as though it were fact.
She threw a tantrum the night before our sons funeral because DH "sounded miserable" on the phone and she took offence, then sulked through the funeral because I was too upset to read a poem she had written.
We went on to lose another baby to prematurity and this relative put our photo's of our daughter in a box of rubbish, asked if she was born with all of her face or with bits missing (she was tiny but perfect), and told us our children didn't count as proper grandchildren.
It took months and months for us to come through the shock and upset of our losses, which were very close together, just eleven months between losing our son and losing our daughter.
The nasty comments and gossip had carried on throughout, right through to after we had another baby, fortunately this time all went well. But this relative wouldn't stop making these comments and when confronted, took offence and started spreading lies and blaming me for upsetting her rather than the other way around.
It was awful and again it went on for months. Eventually it was easier to cut contact altogether and I feel much better for it. I believe part of the problem was that this relative likes to be the centre of attention and hates anyone else to get any sort of sympathy or special attention, even though we would have given anything not to be in that situation in the first place.
I'm sorry your relative is being this way. I'm guessing she is a very close relative, so cutting contact might not be easy if you do decide to go down that road.
Our other relatives have found it very hard to understand, it's meant we've lost contact with more than the person concerned, some have taken their side, others just seem to have fallen by the wayside because it's hard to see them without also seeing the one we have cut contact with. I've had a lot of abuse from one other relative in particular, another just cut me off completely.
It's not easy. But it has been the right thing for us because continued contact with the relative in question was making me ill.
I hope you can find a solution that suits you and that you will be alright. 