I never liked Erynn for two reasons:
1. When Ethan bullies the MC as a kid when he professes his love for Erynn, she stays with Ethan rather than going to see how the MC was doing... like Alexis did.
2. You mentioned the way they are together. When I read those scenes it reminds me of how a girl treats a guy she friend laddered. She uses him for all kinds of friend and emotional support stuff while giving none of the benefits.
Plus she's always in trouble, always needs help and she looks like a plecostomus.