Bit of background, last weekend my sister got married and it was the perfect day. The lead up the wedding had been quite intense with different things being arranged for every weekend for about 8 weeks prior, my gf only has one weekend day off a week so we and our 1 year old son haven't been able to do "family stuff" just the three of us for a few weeks now. On Sunday morning after the wedding was over everyone was just talking and I brought up that me, my gf and our son will be having a day out this Saturday as we haven't been able to do that for a while, I was talking to my mum when I said this.
Come Monday morning and my mum messages everyone saying she wants everyone to get together this weekend to discuss the wedding. I tell her Saturday isn't good for us as we have plans but we are free Sunday afternoon once my gf is home from work, at first she was okay with this until one of my sisters said she isn't free Sunday. So my mum then rings me asking if I can do Saturday, I said no as she knows we have plans. I could sense it was going to descend into an argument so as a compromise I said we will be home early from our day out so we can all get together Saturday afternoon.
I don't know what is going on with her but as she is getting older she is getting worse when it comes to family gatherings and is constantly arguing with me when I say I have plans for something etc. We never used to argue when I lived at home but since I have moved out we constantly argue and I really don't know what to do about it. I have called her out on her behaviour in the past but she just doesn't seem to listen.