since your questions are going very into detail , i hope my english is good enough to express myself properly.
i think she was always on the positive side to gain a bit especially she wanted to have bigger boobs. she showed me some photos of her where she was stick thin with nothing more like a small b-cup. on the other hand she saw some photos of my 2 ex-girlfriends. the first one had pretty big boobs for her age (80F for age 16 - sorry i am not allowed to show you a photo) and the second one was already pretty big size (over 200 pounds). so she found out about my little secret very early. then we had some discussions and she wanted to stop dieting to get her body type into a little different direction. especially for the reason she wanted to see if her boobs are growing during the gain. from this point on i really told her everything about my preferences and showed her some of the internet-girls i really like (bettie pumpkin, mandy majestic, eliza allure, lexxxi luxe). the more pics i showed her the more she was interested into this.