I had a beautiful relationship with my DDad before he passed when I was young. DMum moved out of family home and into mental health facility due to alcohol and drug abuse, threats to kill myself and siblings, and self-harm.
I was placed in the care of DSis and ended up spending years being emotionally, physically and mentally abused by DSis, DBrother and DSis' boyfriend. I was used as a cash fund with SS giving DSis money for school transport, but I had to walk 6 miles to school because she wouldn't give the money to me. I was kicked out of home after refusing to hand over 100% of my earnings to DSis as rent (still expected to buy own food, pay for transport to earn said earnings etc. with no money left) on a regular basis.
Met my fiancé at 18, in the midst of some of this. We began a relationship a year and a half later and his family welcomed me in straight away. His parents were amazing when they found out about the abuse at home. They supported me in getting into college, through four years of university and in general day to day life.
Within the first year, MIL(to-be) held my hand in hospital as I miscarried (on medication alongside the pill, complete accident, but still painful experience). Own family were nowhere to be seen, then DMum popped up three days later saying she had cut her wrists that day and was in hospital herself, and that she'd had two more miscarriages than me, so it's not that big a deal.
Years have passed and my relationship is still not great. DSis has children, who realistically are the only reason I keep in contact. DMum still chooses drugs over a relationship with me, but likes to think she 'makes an effort' by sending a text once every two or three months. If I do the slightest thing 'wrong', they go crazy. DP and I bought his mother a figurine she'd wanted as a thank you for something one day, and DMum flipped, calling me a spoilt bitch and that I'd have nothing without her. I've worked since 14 and have paid for everything I have myself.
DSis ruined graduation, assaulting me in front of her children and my ILs. She blocks me from their day to day life if I tell her no to money, no to babysitting, or if I don't cater to her every need. They're still emotionally abusive to this day.
I think it's safe to say that DP saved me. Along with his family, he's helped me to build a life that I never thought was possible. After five years of being together, my mental health is better than ever, we have our first home, rescue animals, great jobs and he asked me to marry him. Now we're finally planning our wedding. DSis and DMum are expecting to be there, talking about what they can wear and who they can invite, but I don't want them there. We booked a big venue, but have since decided that we want something really intimate, and certainly don't want DSis or DMum there, but we do want DSis' children to be there.
Any ideas on how I can approach this? AIBU to not want them there?