When they introduce the characters she was 7 and he's 12(same age as the older brother). She should be 10 now (since a year went by then two more) and he should be 15. 5 years part. (Believe it or not but 3-5 year age gap is pretty common in the real world). (I kinda understand your point of view on the mouth to mouth thing though...)
Confusing words. But I get it. Your saying, now is not good cuz they young. But in the future it's whatever, right? But he was only doing it with the intention of helping her, not to take advantage of her. (In a previous comment I stated something similar on the topic about the mouth-to-mouth thing.)

Ew. Did he really just do the medicine mouth to mouth thing?