I don't think the size difference is going to matter, however one drake to ten ducks is (in my experience) the preferred ration of male to female. I have had drakes rape and drown the females to death when there were not enough girls to go around.
Not saying it is going to happen, but keep an eye open for that sort of thing.
o GOODNESS. I will keep watch they dot abuse her. The pekins were a "gift" of sorts. They didnt make weight at the local fair so we brough them home.Never crosed my mind about Daisy. She can always fly to get away I guess.