That doesn't sound that cold for ducks. We keep ours in during the day when it gets super cold -15f. Just make sure everything is clean, and add extra bedding to keep in the warmth.
It kind of looks like your duck is not fully dried off. Before putting her in cold conditions wait until she is fully dry. As for her foot, have you noticed other ducks picking at her. If so you could separate them. My ducks beaks have been cracking too, it think it is just from the cold.
Welcome! :frow I am sorry to hear about your lost duck. I know this was already commented, but ducks are social and need a buddy. Ducks are extremely social and unless you can give them constant attention they need another duck.
you know you are a backyard duck owner
When you are in a store and buy stuffed animals for the ducklings to snuggle in.
When you talk about your flock to people describing in detail what they are like and their personalities. (they might look at you funny, but who cares!).
And when you have...
you know you are a backyard chickens owner when you find freshly layed eggs eggciting
Why doesn't everyone?
OR when you walk into a room of people and one of them pulls of a feather, and you say "oh that was probably from one of my ducks." (I own ducks).
I have ducks, but I have been feeding them Purina flock raiser which is supposed to be for both ducks and chickens. I just put oyster shell on the side. hopefully this helps. I have read somewhere that since the flock raiser has a lot of protein in it for young poultry that treats on the side...
I know Avian Fashions has some diapers and harnesses but I don't think they sell booties.
http://www.flightquarters.com/bird-diapers/category/duck-goose-products.html
I have really good news about our little Pekin duckling.:celebrate we talked to someone that has owned ducks for quite a while and she said that she probably just gets really overheated and lies down because of it. That seems much more likely because I often find her and the other ducklings...
I just got a pekin duckling along with two blue swedish. I was wondering whether it is normal for pekin to wander to where they want to go and lay down. Is it? anyway my pekin is the sweetest duckling. :)