oops i reread and see you do have mostly girls that’s great! ( it’s pretty early in am my eyes are fuzzy lol)welcome! sounds like you are doing the right thing. when one duck is picking on others, separating into a timeout is what we do.
If she keeps it up as they grow, the most important thing they need is a large area/run/yard/pen, with lots of places to get away and hide from each other.
Do you know how many males you have the Drake to Hen ratio with ducks is very important. you need four or five hens for each Drake. over breeding causes injury and deaths and that’s what happens if you don’t have enough girls for each Drake.
With the geese, there will be fighting if you have too many ganders as well. Hopefully you have mostly girls. do you know their sexes yet?
post in the ducks forum as @LTAY1946 has given link. and please post pictures of your set up
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