Barnhart Birthday Girl (we have two!)

Soon there'll be a birthday girl, whose name I shall withhold;
I'll write a little riddle and you guess who and how old.

She didn't use to smile a lot, when she was very young,
A pouty lip would often protrude well beyond her tongue.

And then would come a backward kick to ward off woud-be teasing;
Ah.....you know of whom I speak, but now she's much more pleasing.

In fact she wants to help mankind, Music Therapy to them bring;
And one of the ways to do so would by by gui'tar string.

So as you solve this riddle, and guess just who she be,
You also may be wanting a birthday ide-e (altered for rhyming purposes!)

She wants to buy a gui'tar and play with lots of soul,
And grateful she would be for contributions toward her goal!