Why not just call it Wendy? It's short, will sit well beside Dave and can still keep the W as it's on screen look, same way that Drama has a D logo for themselves.
Think you've totally missed the reason that Dave is called Dave though... How many friends called Wendy do you have? (The theory was, I think, that every 'bloke' has a friend or a mate called Dave...)
I don't know anyone called Dave or David in my personal life, either family or friend.
I just think W is a silly name on its own and it probably won't stay that way for long. If it is a female skewed channel now instead of general entertainment like Watch is/was, then I think a women's name, even one not beginning with W, would have been a better idea.