The state mandated ratio is 1 parent to 3-4 kids at that age? You are a brave sole for taking on that challenge!
Just like one of the other mom's said, get a schedule, and get one quick - and stick to it. That way the kids will be better off knowing what to expect.
Have a notebook to record times of booty changes (typically every 2 hours according to the daycare we used to have our daughter at), feeding times, nap times. You could make columns across the top (one column for each child); then each row write down the time, and what happened (9:00 - booty changes; 9:30 - snack) etc. That way, the mom can see what happened about when (and it will come in particularly handy when the kids begin teething - you can tell when you gave the kids tylenol or motrin last). (The daycare's have a sheet similar to this they give to the parent's each day.)
Make sure there are 4 "chairs" the kids can sit in...she probably has 3 high-chairs, so where's your little one going to sit while they're having a snack?
If there's any way to swing it, have there be a set "nap time"...or "quiet time"...turn down the lights, put on soothing music, etc. "Finding Nemo" was always great for my oldest at calming her down.
Just a few thoughts, for what it's worth.
Good luck!
