Fmil.... long read but i need to vent

The day we got engaged my FMIL started really being a lot, and by a lot I mean she immediately told us that she gets to invite 35 people that she would pay for my parents get to invite another 35 and the we get to invite the rest. She also made comment that someone I had not even met asking her if I was going to a bridezilla or is she was going to be a MILLzilla??? She has always been very opinionated while we have been dating but I kinda expected that now that her son has chosen to make me part of the family that would kinda solidify that he trust me completely and it was us as a team now rather then the umbilical cord stretched a crossed town to her. When we stated the wedding planning process such as looking at venues we invited both of our sets of parents to look with us to try to include them. My parents where great and seemed to really enjoy being included but my FMIL and FFIL seemed disinterested in looking with us. My FMIL especially had many negatives she found with each place. My mother had a coworker who recommended a mansion style venue that we went to look at as a couple with my father as he is retired so he was able to come look with us. We both where taken by this venue and ended up picking this venue, which ultimately is expensive but we are able to afford it if we are frugal over the next 18 months. We where thrilled to have found our venue, to share the news with my in laws however my FMIL saw how much we where spending PP she promptly added up the amount and stated that would be the amount she would contribute to the wedding. Flash forward a little over a month my mother/best friend suddenly died, we had already sent out the invites to our engagement party that my parents where hosting, to which I now wanted to cancel but my father convinced me my mother would have wanted us to have the party to celebrate as she was excited we where getting married. In swoops my FMIL again giving us a hard time about the invite lists for the party prior to my mom passing then gives us well me a hard time about still having the engagement party then ask if we want to push the wedding which is still 18m away. I told her no? She states she thinks it will make it easier when we finally get married. I let her know that no matter when we got married it would be hard regardless of time line. The engagement party goes on fine and my dad was right my mother would have wanted us to have a nice night, even though she wasn’t with us I know she was watching over us smiling.
For our engagement gift my FMIL got us champagne glasses which after going through my mother’s things found messages between the two of them where my FMIL is asking if I would like them to which my mother tells her that they are not my style, but she got them anyway. When I opened them my FMIL tells me that we can exchange them if I don’t care for them which I like politely asked if we could. I brought them over to their house shortly after the engagement party to which again she informs me of all of the issues she has with the venue we picked, it’s too expensive, it’s too white ( she and my FFIL feel it lacks color in the decor) as well as other things that she find wrong with it. I told her well your son and I really like it and my mother knew where getting married there. To that my FMIL states well your mother didn’t get to see the venue so it wouldn’t make a difference anyway now if we changed locations as my mother was working when we went to look at the venue for the first time. I didn’t know what to say to FMIL and let very upset. At this point due to everything in my life my feelings are fried. It’s only gotten worse from there with my in-laws. We finally talked to her but I am not sure it made a difference. Does she get a say in things, if so what? Please help, my fiancé is on the wedding planning isn’t fun anymore train so am I. Eloping sounds like fun but that isn’t an option now. Thank you for reading!