She really won't mind that much. To Ducks water is water regardless if it's a pan, a kiddie pool, or a acre large pond. As long as they are given the opportunity to swim they will be happy.
They're not a wild breed though. What she's describing is most likely a released pet domestic duck. They're domesticated and are not designed to fend for themselves like their wild counterparts. Her taking them in would actually be the best thing for the duck and her ducklings.