Welcome to BYC Fellow duck momma!!! They are simply adorable, how old are they? Sounds like you're doing everything right. You won't know their sex until at least 7 or so weeks but you may be able to tell by their voices - girls will cheep and are loud whereas boys will sound more like a frog or a 'meep' and they are generally quieter!
It's lovely to meet someone new to ducks. I have two 10 month old ducks and now we have 4 week old ducklings. When I first started I literally didn't have a clue but I've learned so much so fast and you will too!! This site is rife with information on ducks, from coops and runs to food and treats! I hope you enjoy, everyone on here is very helpful and kind and will try to answer as many questions as possible.
I will also do my best to try and help you learn what I have learnt these past few months! Feel free to share lots of pics on the duck forum!!