I feed my hatchlings and juvies about twice a week. Once every 4 to 5 days, generally. I've never had them refuse a meal except sometimes when they are in full blue. I say let nature decide how you feed. If they act hungry, feed them. Nature knows best and knows when it's time to eat. If they don't want to eat, then they'll refuse and you can just try again later.
About the pooping thing, I wouldn't worry about that. She'll probably "go" in the next couple of days. If not, I still wouldn't worry about it. There's another thread about that and one person said his/her ball usually goes a few MONTHS without pooping.