I think you’re right in that it would be in character for Adalind. I’m really glad they didn’t have Nick be all suddenly gung-ho in love though, because it would have been terribly out of character for him, even if they didn’t have the history they have.
And I still don’t think they developed it enough for it to make sense for either of them to feel anything except cautiously amicable toward one another at this point. I’m not sure they can go back and fix it now, because they just rushed it for whatever reason and now a lot of fans are left scratching their heads going “where exactly did that come from?”
A couple of episodes ago she was perking up at the sound of Meisner’s name and blushingly, hopefully asking Trubel whether he’d ever mentioned her, and now she’s in love with Nick? Not attracted to, not beginning to have feelings for, in love.
Adalind may be a lot of things, but sentimental she’s not. This direction at this juncture doesn’t make any sense for her and is horrible for Nick. I just don’t know what to do with it except throw up my hands and try to watch around it for the rest of the plot.