Keep an eye on them and be ready to jump in if a catfish or bass tries to eat them. I've seen both eat small ducks in the creeks and ponds around here. I've caught lots of bass that you could easily put a softball in their mouth, even a few that you could stick a football in!
Adorable! That creek reminds me of the one down the street from my old house in PA - only got dangerous during rain storms and snow melts, rest of the time it was just deep enough to get your ankles wet.