Yep, leave with mum - that's the joy of broodies. Find some way of putting them into a small run and then you can just leave her to it. Don't worry about the paint tray for a couple of weeks. They don't need that much water to begin with - just enough to drink. They're not waterproof until they're fully feathered but they can swim whilst still fluffy - just not for too long and don't let them get chilled. I've got a broody with six goslings at the moment - they're five weeks old and all towering over her but she's still brilliant with them. They've just gone out in the open for the first time and she keeps them in close, takes them around, stops the ducks picking on them etc. Without a broody, you have so much else to worry about!