Nah, Velma never shaved down there- she liked the unshorn look as much as possible. You should've seen her when she waved goodbye. You didn't think she wears those bulky ass sweaters for just warmth, right?
Daphne however, was very vain, and had a propensity to keep her clam bald for Freddy. Too bad she & the rest of 'em could never pick up on the ascot was a foreshadowing of his alternate lifestyle. BTW, according to Josie from the pussycats, Fred was only a shower too.
Shaggy, well, he didn't always make up excuses to give Velma her spare Glasses for nothing. Turns out Velma found out he is mega hung when she found him & Scooby-Doo pissing in a field during one of their 1st investigations. She always bribed Scooby to get lost for about 15 minutes with Scooby Snacks.