Congratulations on the new surprise today!
I'm glad she's bossy lol! Did the vet look into her mouth and do you have an idea of an approx. age?
Foals don't begin erupting anything to chew with til they're 1-2 weeks old, then they'll start being pretty curious about what mom's eating. If mom's bag remains nice and full and baby has a milk mustache and doesn't appear to be frustrated and pushing into the teats, or coming back to try and nurse far too frequently...well, you'll be able to tell. If you think you need milk replacer for the first week or two, hopefully you can order some, and I hope you won't need it. Some folks use goat's milk if they have to. Glad they are both ok!