[Tijeras_Slim]

And there’s no linguistic connection with “Guenevere"

Sheesh, fooled by the internet again!

[Tax-chick]

It sounds very similar! However, Juniper was in use as a name in Italy for centuries before the Arthurian cycle took shape as literature. Iirc, the Celtic name that was Latinized as “Guenevere” is “Gwynhyfar”; you can see how that would develop into Winifred and Jennifer.