This is a fun subject. It can be difficult to come up with the right name for a character. In Daisies I tried to have a range that reflected the different ages, socio-economic backgrounds and cultures of the characters. Conventional wisdom recommends not giving characters names that start with the same letter, so as not to confuse the reader. I'd go further and add that I try to avoid too many names that end with -y, as in Bobby, Jackie, etc. or are the same number of syllables.
Paula Holliday is named after my sister Paula, who passed away while I was writing the book. The Holliday comes from Judy Holliday who was one of our favorite old-time actresses (I highly recommend Born Yesterday, and Adam's Rib, two of her best movies.) Renata is the name of a very dear friend of mine. The book is sprinkled with the names of friends and the children of friends but I made sure that none of them was a victim.
Two other notes...my editor asked me to change the name of the killer because she thought it was too hard to pronounce and I've never gotten used to what he/she is called in the book. And I've recently returned from a mystery conference where a fan bid on and won a character name in my next book - so there will be someone named Nina Mazzo in book three of the Dirty Business series.
Cheers!