Do I (M28) allow family that kicked me out at 18 to move in with me and my fiancé (F27)?

Holy cow, do I ever need some help. Background is important here, so please bear with me as I go through it. <br><br>I’m 28, and my fiancé is 27. We are reasonably successful, upper middle class, and very stable. We have a 7 room house of good size on about 2/3 acre of land in a very nice, safe neighborhood with good schools. We have been together since her Sophomore year in college (11 years). I was able to join a very lucrative field straight out of high school (I am a wind turbine technician) and she holds a good job in HR at a hospital. We are set to be married this coming Spring. We are very happy. <br><br>I have four sisters and no brothers. Growing up, it was a generally stable environment, but it wasn’t happy. My father was an alcoholic of the angry sort, and my mother worked 60+ hours a week to keep us fed and house. I am the second youngest, and I had to fight incredibly hard to get an education. My parents did not care; they wanted me to be a laborer because it was a “respectable job” and they were mildly abusive about me leaving the state for college. When I graduated high school and got accepted, they more or less kicked me out in my Beater car with about $3,000 and told me to not come back. It didn’t bother me much, as I was leaving an unhappy home anyway. <br><br>The reason I was allowed to stay past 18 is because I am the only member of the family that has any ability in medical care. My youngest sister, Ellen, has a serious genetic disorder that will kill her if she is not cared for. She is handicapped (both physically and mentally), and she is in constant need of care. My parents have used that care as a method of controlling my siblings their whole lives. I was taken to countless specialist appointments, months worth of camps, and I was a full time care provider for her my whole life. I loved her with all my heart, and I did not begrudge a second of that time. <br><br>From the time that I left, I have spoken to my parents maybe 5 times, and my sisters about 100 more. My siblings and I have arranged that once Ellen is gone, we are never speaking to our parents again. My parents are wholly obsessed with my youngest sister for some reason. When my second youngest sister, Beth, got pregnant with her first kid 5 years ago, my parents did not come for over a year; they said that taking care of Ellen was far more important. <br><br>I haven’t seen my family once in six years. My parents valued their pre-teen child over their adult children. My siblings and I are very close for the circumstances. Once I left, I immediately cut ties with my parents. <br><br>Last week, I get a frantic call from my mother. She brings up marriage, kids (we have discussed having kids after marriage, but nothing beyond that), and that she is getting too old to care for Ellen properly anymore. She said she would like to move in with us once we are settled, and that she would bring Ellen with her. Then she brought up the fact that my father suffered a severe heart attack over the holidays, and is in need of full time care as well. She asked that we take them in. <br><br>I was floored. We have discussed this possibility (my younger sisters and I), and we have decided before that we would never do this. But now that it is a reality, I’m having some doubts. I believe we all are. <br><br>After taking some time to calm down and think about it, I called my younger sisters and we had a very lengthy call. Beth and I are against it, but we are also each 3 hours away and could avoid them if we needed to. My other sisters are positive that it would be a good idea. They say that mom and dad need us, and Ellen needs a family to care for her. We need a consensus before we make any decisions. My fiancé is against it as well. We have spoken about having kids, and she doesn’t want them around my parents or sister. <br><br>So, what do I do? I have never had any real family (I don’t count my parents as family), and I have always wanted that. But at what cost? It will destroy my relationship with my fiancé, it will add an enormous amount of stress, and it will change every single plan we have ever made for our lives. Does a mom get a second chance? Does a sister that can’t care for herself get a place to live? Do I ignore my fiancé and take them in?<br><br>I know this is a long ramble, and I apologize for that. Please: help. I don’t know what to do.