Adalind is desperate now that she can't depend on the Royals, so trying to make allies with Nick's group is pretty smart. I'd rather her be with Nick's group where she can get some actual interesting storylines, than stuck with the Royals for another season.
I'd probably agree with you
if I found Claire Coffee remotely appealing as an actress. Unfortunately, I've always found her insubstantial and mildly irritating. I do find her almost sympathetic when she's playing Adalind as vulnerable and yearning for her daughter, but she's still a mediocre actress.