Every year we have a theatre outing which several family members go to. Over the years we have taken sil and as time has gone on, her eldest. She now has two DC.
More recently mil and partner have taken two cars in order to pick them up. This year we have been asked.
Whilst we don't mind as such, although one booster seat and two others will be a squeeze in the back of our car, we want to do some shopping before the matinee so want to leave in good time (1 hour journey, so leave at 9 ish). There at 10, 2 ish hours shopping, lunch all together then the show.
Have been told by mil that sil won't like that and will want to leave later!
So AIBU to tell her to leave when we want to in the morning or if she doesn't want to DRIVE HERSELF!!!!! (She is able to do this, but has not done so once in the past 15 years)