Terminally ill MIL behaviour - what should we do?

[WhyTheHeckMe]

I just want to vent and get advice I guess.
My MIL is terminally ill, she's been told she has around 2 years left
Our relationship has always been a little strained. She lies to make everyone look bad but herself and has been caught out numerous times.
She has 5 grandsons from my SIL and 1 grandson from me and dh.
I'm now pregnant again and all she ever goes on about is how we are going to give her "yet another bloody grandson" as she is desperate for a granddaughter . We don't want to know the sex again and she said we are selfish for not "preparing her for the worst".
I find these comments so hurtful. I miscarried earlier this year and can only hope for a healthy baby. How does she think this is okay?
We also found out over the weekend she has announced the pregnancy to all of her side of the family. I mean all. Grandparents, SIL and aunt's and uncles.I'm only 9 weeks.
Dh is upset that he won't really have anyone to share his news with himself now.
We feel we can't say anything to her because of the illness and she will no doubt make out she's done nothing wrong and tell everyone how awful we've been to her! Ahhhhhhh. .

It does sound a bit toxic, but you won't win. Just rise above it and do what is right for you.
more importantly, Congratulations!

Calm but factual responses "as far as we are concerned there is no 'worst ' to be had in the birth of a baby" "we just had a distressing miscarriage, it's a bit upsetting that anyone can think that any baby is a disappointment " " you have made your preferences clear, we'd like to get on and enjoy looking forward to a baby, so we don't need to hear any more against boys, thank you"

Do you think treatment/ mental health might be affecting her mood and outlook, or has she always been like this?