Well, it looks so simple, but I miss parts of it. It's a folk song from Silesia, which is now in Poland- or is it from Schleswig-Holstein near Denmark? And then I don't know what wuerst is (not Wurst, which is sausage) - I think it could be a variation of waerest, which is the second person singular present subjunctive of "to be" - so I'd translate the first line, "Rosie, if you were mine." And "Nu Ja..." could be considered a noncomittal response, or maybe it HE that's saying it, just to carry on the conversation...

OK, so here goes:

He: Rosie, if you were mine...
And do my wishes?

She: I won't do your wishes.
I'd rather slug you in the face!

He: Rosie, go pick somekindaplantformakingwreathes (Kraenzelkraut)
You are to become my bride.

She: I'm not gonna pick somekindaplantformakingwreathes
I am young and I'm not getting married.

He: You are young and not getting married?
She: I am proud and I don't like you!

And to come up with that, I took two years of German in high school, one in college, 8 months full-time in the Defense Language Institute, and lived in Berlin two years. Maybe I shoulda stuck with Latin and Greek. Actually, I knew what it meant, but translating is another matter.
-Joe Offer-