Not to redirect the conversation, but out of interest I Googled "gaby," and this is what came up at dictionary.com:
gaby [ gey-bee ] noun, plural ga·bies. British Dialect.
a fool.
I didn't know that one. Maybe Ben's familiar with it.
And of course, any self-respecting cartoon fan should remember Gabby from the Fleischer picture Gulliver's Travels, and his own subsequent cartoon series.

Not to mention Gabby Hayes, of course, whom the Pixar character was undoubtedly named from.
So, it's just funny how your friend got your thinking turned around on that. Just about any other Gabrielle out there with a nickname is "Gabby," too. But I suppose there could be other Gaby's as well.