female ducks can be kept with chickens but theres some differences in their needs. Ducks need at a minimum 4sqft per bird, with chickens I'd probably give them even more. They dont usually care for nest boxes, and they generally dont roost so you need some floor space of your coop without roosts above it so your ducks dont get pooped on all night. ducks produce a lot of moisture through their bodies and their poop so your venting and bedding needs to take that into account. Ducks require water if theyre given access to food, so if you want food inside the coop you need water there too. Ducks need water deep enough to dunk their whole head into which can get pretty messy if you dont use the right kind of dish, and deep water is a risk for baby chicks. The bottoms of their feat are more meaty and more prone to bumblefoot issues so you need to tailor your coop and run floor and bedding to suit that. Ducks dont usually do well with steep ramps so a raised chicken coop could make it difficult for you to get them to come and go on their own, you'd want something low or sitting on the ground.
You should definitely not keep male ducks with chickens as a male duck trying to mate a chicken (and it will) can easily kill it.
You still might run into complications, theres no guarantee that everyone will always get along, so if you want to try co-housing I'd be prepared with a backup plan in case it just doesnt work out
