Bill,
I don't believe you'll gain much in the way of file compression by zipping the MP3s, which are already fairly compressed. And, I'm not sure if you can unzip a compressed folder with the Droid. Might be better to just place them all in a folder and send the entire folder to her.
Good Luck,
Gary

_________________________
PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!
K+E=W (Knowledge Plus Experience = Wisdom.)