This cache is named Shirley because the name of the nearby road is "Lavern" and I just can't imagine Laverne without Shirley.
Shirley Wilhelmina Feeney, played by Cindy Williams, was the perky, positive one of the duo. She was meek, sensitive, and prone to overreation. Shirley worked at Shotz brewery with Laverne. She had a lucky charm named Boo Boo Kitty, which was a stuffed cat.
Another notable Shirley lives in this area and will surely be seeking out this cache!