Is it normal my friend thinks kissing is gross?

Freshmen and mature is an oxymoron.

To be honest, I think a lot of children consider themselves to be "mature". They're facing child's issues after all.

When one becomes an adult and starts facing adult issues that's when things change.

So likely your friend may feel that she's mature now, but give it a few years and she may grow out of it. And likewise her tastes in romance may also change as she grows up.

I won't speculate on the supposed maturity of your friend, because she may well have her head firmly screwed on (or not), idk.
But as someone who is seriously averse to germs, I can say I feel similarly - and while it's not normal, it's not exactly unheard of.

The only thing I would say is a bit iffy, is that she doesn't think sex is "gross" too? Slightly confusing. Surely a hell of a lot of germs are transferred through that, also.

Sounds immature and naive to me.

Kissing is gross, your friend is totally right. But sex is even more gross. Lots of things are gross

I used to think kissing was gross too! Then I fell in love and now I don't think that any more.

No she is lesbian I bet... Eventually she will refuse to even have sex

Ridiculous!

I think that a large portion depends on cultural/ethnic backgrounds and on how a person was raised as a kid.

For instance, some abused people think that sex and other things related to it are "gross" or "wrong" due to the things they've experienced. Though, this doesn't have to mean that your friend was or is being a abused.

I personally am disturbed by relatives kissing each other on the mouths. I think it has to do with the fact that I sexually abused as a kid and kissing or attempted kissing on the mouth, was one of the methods implemented.

I've heard people say that before plenty of times on this site.

I knew a broad who would suck my cock but not French kiss. Didn't bother me. She even let me cum in her mouth. Never want to French kiss after that anyway...Her name was Tina..