From wikipedia entry on P. Street:

Her given name was inspired by the nearby Idaho town of Picabo, Idaho, (pronounced "PEEK-uh-boo"), which in turn takes its name from a Native American word meaning "shining waters".

Whenm she was au courant, the story was that the 'rents had not given her a name at birth but allowed her to choose her own when she became old enough to talk. Sounded too glib back then, even.

TEd