Yeah she was. Maybe I'm only seeing this from a girl's point of view. I don't know. If I were Nick, I would have accepted her. I saw that after his initial rejection, her personality changed more drastically. He was too slow in making up his mind to help her. If I were a Grimm, I'd be scared FOR her rather than OF her. As you said Nick loved Juliette deeply and would know that she stood by him through all his rough patches so If I were him, I would do the same, no matter what the obstacle.
EXACTLY what I thought of Adalind when she lost her powers. I don't believe the 'motherhood' can change you statement applies to Adalind. She was ready to sell her first kid on the Black Market for her powers and only really develop a conscience towards her daughter later on in her pregnancy.