Will i be the asshole for not inviting my soon to be ex-stepmom to my wedding

i (34F) got engaged a little over a month ago to my fiancé (41M) and i have been so excited to plan my wedding. The thing is my dad is currently going through a divorce and I'm not sure if i should invite my soon to be ex-stepmom to my wedding.

Some back ground info my dad married my stepmom in 2007 after about 2 years of dating, so she has been in my life since i was 15. she has been there through many things but she has cause some problems over the years. also i have a stepsister that lives in another state that is amazing and i am asking her to be a bridesmaid but she was not raised by my stepmom she was raised by her grandmother (her dads mom).

while we have had issues with stepmom over the years she has been there when i needed her many times. she was the first person the show up when i was in my first ever car accident among other things that have happened in my life she has been there when my parents couldn't. as well as many other things i don't have time to mention.

In recent years she has been more of a problem then anything else, like a couple of years ago my little sister (27F) moved to a different state to live with my stepsister (33F) and her husband, well that year my stepmom went to visit for thanksgiving alone and while there she was caught on the phone complaining about how they kept ignoring her (not true) and how they had planed noting for her to do with them. While on this call she even said how she would rather "kill herself then spend anymore time with them". after that my sisters just wanted her to leave which she did the next day. both my sister really began to distance themselves from her.

about a year later my little sister move back home but instead of moving back in at my dads while she figured out her life she moved in with my best friend of almost 30 years not to stay in the same house as step mom.

now about a year ago my stepsister found out she was pregnant but she unfortunately she had a miscarriage. well upon receiving this awful news my stepmom told her daughter that it was God's way of telling her to slow down.

more recently my sister came into town for my birthday which also was the day i got engaged and she decided to stay at my dads one night to spend time with him. while my dad and stepmom are getting divorced they are still living in the same house just opposite ends o the house. well my stepmom came out of her bedroom to eat dinner she told my dad and sister that my sister made her uncomfortable and she felt threatened even though my sister had not said a word to her. the next day my sister cried all the way home because she was hurt and now felt unwelcome in the home we grew up in. i am pissed off about this but have not said anything because i don't want to cause any issues for my dad. my stepsister has told her mom that what she did was uncalled for and that if there are sides to choose in this the 3 of us (me, stepsis and little sis) will choose each other.

so i am wondering if i don't invite my stepmom to my wedding will i be the asshole. i just don't want any drama on the day. i dont know what to do any advice would be great.