Now, be fair to me here at least.
I honestly had no idea about the whole Y-Wing thing. It's not so arbitrary for her to pilot an N1, nor an X-Wing, but if she outright prefers a Y-Wing, hey. That's really pretty cool.
I agree Leia should not be some hotshot pilot, but provide more of a leadership/support role. I mean, she is more of a politician after all. So I'd recommended having her reduce stress on all friendly ships at range 1-2 or hand out free focus tokens or target locks. But any sort of buff would probably be thematic.
And for a lot of you posters... Why would you just arbitrarily have Leia in the N1 (?!?) or the X-Wing? We're talking about a character who has been shown time and time again to fly a Y-Wing. I understand a ton of you people "need" your X-Wing fix, thus want any and everything to belong to the T-65... But c'mon now. Ha.
it's not like we haven't had Pilots in fighter's other than their preference..
Tycho Celchu (preferred X-wings, only flew an A-wing because it was what was available at Endor, according to the novels)
Corran Horn (preferred X-wings, had his own private X-wing. never flew an E-wing in any of the fiction, though the unit he was with did in stories he did not appear in)
Guri (never flew a Starviper ever in any story she appeared in. had a custom armed yacht instead)
etc.
Don't forget Porkins who is an Y-wing pilot through and through: