Idk why she sucked for you, because like others said, she's usually a major butt kicker. Maybe she got RNG screwed? You talking PoR or RD?
I think she needed more character development, but that's about it...but yeah, not liking someone because of pairings...would be closed minded. I don't support Ike x Soren but I use Soren and enjoy watching him pwn things. My friend who got me into FE loves the crap outta him, but that's irrelevant....
Maybe try again? Try not Boyd/Ike/Soren/etc stomping and let her get some kills? Idk...