H.J.
K.- What a pickle. Although you're familiar with Preschool A -You may like Preschool B. A preschool is only as good as the parents. Spend time in the classroom, ask questions, get involved. Although Preschool A said they are willing to stay late...what if they change their minds (winter, schedules, staff changes, etc)then you're really up a creek!
And with your sister-in -law there too you'll have double the eyes and input.
Good luck-H.