Sister in law..used to be my best friend..now..kids ..life etc..got in way.

Ive been with my SO for 21 years...everything was great on holidays but now im no longer invited on holidays cause my sister in law ..(now divorced from a heroin addict so im not sure if shes on drugs or what shes smoking)she has accused me of calling cps on her and of course its his family they find it best just to not have me go to family holidays..i know awful..its been 2 years..lots of arguments over it between me and SO..now we have made seperate plans as we are a family and wont be seperated on holidays..

It was alot of stress coping with a tradition i no longer could attend and my kids seeing me upset and i didnt want to disrupt their holidays so pretty much first year of this madness i was home alone on holidays..

Anyway..i discussed my feelings with SO and now that im pregnant and he knows his sister and his father are not gonna act like adults anytime soon.We are going to his mothers side so we dont have to deal with the drama..and shes alot..

My question is...i dont want her in my babies life after isolate me away from her family i been a part if for 18 years.last 2 years i had to spend without my kids and SO..i was an adult about it and tried talking to them about it.i understand she needs he family now..but...

Am i wrong for not wanting anything to do with her and not letting her in this babies life..i know im liwerinh myself to their level but i refuse to spend and holiday away from my family or sharibg with ignorant people.I told SO..that his dad can come here anytime to visit.But his sister will not be a part of my babies life after all the hurt she has put in my life..

Sorry so long..but am i being unreasonable..or do you undersyand and would be the same way?i cant share this awesome joy in my life with someone who will just cause drama and ruin it...