Unwanted Opinions of a YA Writer

I have written thirteen novels in the genres of YA fantasy, science fiction, and contemporary, and I still have no idea what I'm doing. I am a biology student and spend 6-8 hours of my day talking to flies, so don't take any advice from me.
My Life Next Door - Huntley Fitzpatrick The romance was cute and the writing was pretty. The plot took a really long time to get going. In some ways I think it was justified, because it did require a build up for the most impact, but it could have definitely happened at least 50 pages sooner. I like precocious children as much as the next uterus-bearing person but the author definitely got carried away with some of the dialogue. Some of the tropes--boy from the wrong side of the tracks, loving poor family vs. cold rich one, etc.--seemed a little tired and I wish the author had played with them more. I also found Nan and Tim's storylines and the way they played out odd, especially Nan's. I'm not entirely sure why, but Nan's in particular felt like it petered out into inconsequential nothingness.