Bridesmaidzilla?

Hey i need some advice on how to keep my cool and be caring but also stern.. i have my two sisters in my wedding party, i haven’t sent the official bridesmaid invites out yet but i told my sisters they’d be in it.
one said she doesn’t want to do the updo i picked because she’s insecure about her shoulders and neck and asked if i could change it to half up or down.
the other wants to do her own makeup instead of having the artist do it. i don’t want to sound harsh but it’s my day and i’d like to do it how i’m imaging in my mind and i want the full experience, girls getting ready getting their hair and makeup done in the suite at the venue, the pictures being taken as we do it. the whole shababang. and now i’m just feeling stressed because like i said they’re the only ones that know and i have a total of 9 in my wedding party so what if things happen with the other 7 i’m just stressed and in panic mode