Apollonia:
NiaLonia
Appy
Lonny (eew, but it's possible :P)
Lonie
Apia
PiaAllia
AllyLiaPollo (Chicken in Spanish :D)
Polla
Pollia
Apple
Apolla
OllieOllia
Pony (I'm sorry, I'm not in a very serious mood at the moment :D)
Poll
Ania (I quite like this actually)
Annia
Annie (for if you want to pretty and unusual name a bit more boring)
Anna (ditto)
No nickname is fine, but with five syllables a bit hard to achieve.