Hate to burst your bubble, but I'd already long since decided on a name: Daisy. This is due to HAL singing
Daisy Bell in 2001: A Space Odyssey, which is the same movie that the name Dave comes from. Also, the name is very similar to Dave in multiple different ways while still being clearly feminine. (A few ways being having almost the same number of letters, both starting with same sound, and both starting with the letters "Da")
While there is no real female counterpart to Dave yet, any counterpart to Dave made by me would be named Daisy. She will not exist until/unless I truly make her, but the name Daisy can be used to refer to the female equivalent of Dave. It won't be a stylish marriage - I can't afford a carriage - but she'll look sweet on the seat of a battleship built for two.
Also, I notice you titled the poll as what should be the name of Dave's "wife"? Excluding the subject and implication of the song she is named after - which is what I was quoting above - she's not necessarily Dave's "wife". I certainly don't want anyone getting an image of her staying at home while Dave goes to work, though it might be fitting for the time period the song is from. Daisy isn't just a female reflection of Dave, she's her own woman. She flies her own ships and leads her own factions. Don't underestimate any Daisy. Even though the name sounds extremely feminine and delicate, Daisy is just as active and capable as any Dave. This isn't to say she isn't feminine, just that her femininity doesn't interfere with who she is or how capable she is in any way, shape or form.