There are many beautiful patterned celluloid fountain pens that are attractive to women, whether modern or vintage. But then men like them too. I'd call those classic, rather than cute.
The Japanese brands seem to have a lot of "cute" in mind. I'm a girl and I don't fancy Hello Kitty anything, but I do like pink and have a pink Pilot Prera and a champagne pink Pilot Decimo. Sailor came out with a white Pro Gear with rose gold trim, but I understand that's out of production. It does, however, offer its other pens in different attractive colors (Pro Color, etc.).
I don't really see fountain pens as being gendered. My favorites are classics; it all depends on how you fit them into your lifestyle.