Yes, this is where I am at, it's hard. She is so scared all the time and many of the other birds are quite mean to her, she could relax in my yard away from the stress, she knows my home and me, but she knows the creek too. I also really wonder about the other mallards with her. This creek is on a nature path and connects to a 55 acre nature reserve with 5 ponds that starts about 20ft from my house. There are quite a few various domestic ducks and geese with the wild ducks and geese out at the ponds but they stay separate from the ducks in the creek. Many of the wild birds in our area don't migrate so these may or may not, but they way they all showed up together with no mama, and they way they were so friendly and trusting right away makes me wonder if they had all been domestic. The mallards feet are not marked however.
I didn't even think about diseases, that is a good point because the rouen definitely would need friends and I would really love to get cayuga ducklings at some point. But then I wonder if they would be exposed anyway with such a large amount of wild ducks directly on the other side of my fence all day long. When I go out to feed these girls I now have 24 other mallards and 3 goose families who come to me too lol. They were out there before we moved here, but they got the memo that I had food and come to me now every time I go in my backyard lol. I see coyotes regularly in the pasture on the other side of the creek and I hate that this girl couldn't fly away if she needed to. Just a hard situation.