In laws not coming to bridal shower

My fiances sisters are not coming to my bridal shower. A little back story is my father in law has always told his children that they never have to do anything they don't want to do, some of them definitely take that to an extreme where if anything makes them uncomfortable they won't even think about doing it even if that can mess other people over. My sister in law decided to move 2 hours away two weeks before my bridal shower, which doesn't matter to me but she told my fiance she isn't going to the bridal shower and this was decided before she even moved. no excuse or anything. I am extremely close to her and have gone to her baby shower, baby's birthdays, her own birthday party's and i mean i was literally in the delivery room with her. The other sister in law just no excuse either she said she can't come. I know they aren't doing this in malicious way but I have gone through so many things with them, attended so many of their events and they can't come to a two hour event. They are also tough girls raised by their father where feelings are for kids and if i said anything to them they would say i'm dramatic for sure. Keep in mind i'm not even having a wedding, im eloping at the end of this month and my mom just wanted to throw something little for me. I guess im posting this for validation. Am i being petty? Probably but just annoyed.