Well - this is an interesting Mudcat discussion - covering the subject from A-to-Z. Like playing "telegraph" it is fun to let these things run for awhile. Let us see what an authority might make of it. Mr. Offer (with six years of training) - could verify the Latin donna but most of us might be familiar with its usage as in bella-dona.:
Lighter, J.E., Random House Historical Dictionary of American Slang Vol I, A-G, (The Only Historical Dictionary of Slang, Spanning Three Hundred Years of Slang Use in America), Random House, New York, 1994, p 628.
doney var. DONA.
donna Und. & Circus. a woman, esp. of the demimonde. Also vars.
* 1859 Hotten Slang. Dict.: Dona a woman.
1871 in Asbury Gems of Prairie 99: The oldest dones in the world.
1873 T. Frost Circus Life 277: dona (lady) is so constantly used that I have seldom heard a circus man mention a woman by any other name.
1875 in F & H III 307: A circus man almost always speaks of a circus woman, not as a woman, but a dona.
1877 in Asbury Gems of Prairie (opp. p. 144): "That was a poor stiff that done gave Lieutenant Bell…on Monday night."
1890-93 DN III 307 Dona, Donna, Donny, or Doner … (vulgar). - A woman. (From Italian).
1905 in JAF XXVIII (1915) 184: If yer don't quit a-foolin with my dony…I'll cut yer goozle in two.
f 1908 in DN III 306: Dony n. Girl, sweetheart…."My Dony don' wear no drawers," - a line from a popular negro song.
1917 DN IV 411: Doney …Sweetheart. Also doney gal.
1946 PADS (No. 5) 20: [Virginia Words]….donny: Girl friend; not common.
This thread was becoming so darkly twisted it required a "Lighter - Clarification"
What a "delightful world" of You-Tube scholars and Google ethnologists.