Sister in law problems!!

So it’s a long story so bare with me!

So I’ve been with my fiancé 4 years, he has a very small family all in each others pockets consisting of him, mum, sister and dad and his girlfriend that’s it.. so we met it was over Instagram (I know) 🙈 we live miles apart about 2hr drive.

So at first I got along with his mum and sister everything was fine hadn’t met his dad and his girlfriend yet still early doors but then I found out I was pregnant about 4 months into the relationship and my fiancé decided he was going to move down to where I live and then problems soon started... first his sister started with do you think it’s a good idea abit soon maybe get a termination ect... his mum on the other hand took the pregnancy well so did his dad and his gf then his sister got really upset when he eventually was moving which I obviously understand there siblings about 18months apart so close in age.

So he moves in everything is going well he sees his family as his job is still currently where he used to live but the sister says he’s hardly there and spends all his time with me!

I always felt like I got along with his sister but then my fiancé tells me things she’s been saying to him and other family members which gets back to him so I’m confused if she actually even liked me at all!

Then at 32 weeks we lost our baby suddenly he was stillborn as traumatic as that time was for us she constantly hounded my fiancé saying he should come stay with her and have a break from our relationship and maybe the baby loss was a sign we shouldn’t be together!

Well he stayed living with me and eventually we fell pregnant again with our rainbow baby and the whole pregnancy she told everyone that would listen to her in the family that it was all so rushed this new baby and that I yes I had no consideration for the family’s feelings and it was all to soon and rushed!! She said that I’m quite an immature person for even considering another baby and that the family hadn’t even grieved for the baby we lost and I just shouldn’t have kids.. I have a 9 year old from a previous marriage and am 33 and so is my fiancé so she was basically saying I’m a shit mum or something.

Well I couldn’t no longer hold my breath I told her that it’s not her place to say these things and it’s hurtful and upsetting that she would even begin to have an opinion on my life when she barely knows me and it’s her brothers life and I don’t force him to do anything and where simply in love and want a family together and that it’s none of her business! I told her that it’s up to me and her brother to decide when we’re ready for another baby and that We was grieving too and she’s out of order.

My partner also got offended by her behaviour and comments about our relationship and the baby we lost aswell as the baby I was now carrying and told her where to go basically.

Not once did she apologise for all the disgusting behaviour of hers and we haven’t spoken to her since... so my baby is born safe and well my fiancé mother comes to see the baby and asks if His sister can come to... I know I should of let her come but I said no not until she says sorry for all her comments and the stress she caused me through my pregnancy.

She then messaged my fiancé to say that she’s gona tell everyone that I’m keeping her nephew from her and that I’m a evil person! I rang her and said I’m not an evil person and why would you want to see a baby you said was rushed? I know it’s petty of me but I told her why can’t you just apologise? She said I took her brother from the family and that she was close with him like besties and then I came along and stole him and she stands by everything she said and that we shouldn’t be together.

So at this point I feel like it doesn’t matter what I do she’s always going to feel this way about me! His mum always says are you speaking to your sister yet to my fiancé and he says no and it’s like his mum thinks we’re going to just forgive and forget?! Not only did I lose our baby I was pregnant and had a terminally ill father that I watched slowly die as well as a 9 year old to look after I feel like she added so much stress onto the already overflowing plate I had and it wasn’t needed so I can’t forgive her words!

So my baby is 8 months old and never met his auntie and I don’t know how we can possibly mend all the damage she’s created over spite, jealousy and the feeling of abandonment of losing her brother and there close relationship!

Any advise please? What should I do? Can this be mended?