I like
Wendy, but it feels somewhat juvenile to me, probably because
Barry likely got the baby-speak "fwendy".
Gwendolen is lovely and I think
Wendy is a nice nickname for that, and more interesting than
Gwen, which seems to be getting a bit overdone.
My boyfriend has an aunt named
Wendy, she's in her late 50's (?) and that's probably the age group I'd associate it with. I don't hate names from that generation as much as some people seem to, but they do feel dated since they are most people (who are having children's) parent's names.