I do understand what you mean about "girly" colored knives... but I guess that at the time we get to live... we should better reffer to "bright colored knives".
I, myself, am a sucker for anything colorful. So I have a Spyderco PM2 with pink G10 handles, an Ontario Rat2 in pink, a KaBar Dozier Hunter D2 in blue, Spyderco PAcific in Green, Spyderhawk in orange, another Military in Orange, a yellow minigriptillian from Benchmade...
Colorful handles take some of the edge of the tool at the eyes of non-knife people. They serve the purpose of being "cute" and also help finding them when misplaced.
My daugther (9 years old) has a Ka-Bar Dozier Hunter with Orange scales and a Mora Safe (blunt point) with green handles. She sometimes struggles with the spring on the lockback. Also, since she bites her nails, has a problem with SAKs in general, unless it is a Soldier or OHT. A recent purchase of mine that she uses, opens and closes with no problem is a Civivi Conspirator (flipper on bearings + button Lock).
While they can operate pretty much any tool, some features that we, adults, take for granted... are not for them. Such as strong springs or anything that requires strong pinching action. Some linner locks might also get tricky.
I suggest you find a knife for her that YOU like (and comes in a variety of colors) and let her choose the color.
Mikel