It's today Friday. She told me that she'd tell me by today, and one of the other moms (my very close 2nd choice) needs to start transitioning next week, so she needs to have her daycare secured by today.
I sent a short email telling 1st choice that I didn't wish to pressure her, but that the other family waiting need for me to give them an answer by today, and that I thought I'd be fair and give her first refusal.

Now, I will wait an hour or two before moving on to the other family, I guess!

Playfelt, you bring up a very good point re 2nd pregnancy possibility! Thanks for that. It's something I hadn't even considered.