My best friend is having issues and I'm not sure what to tell her.?

You CANNOT take out the most important issue in the relationship - AGE. Ya'll are behaving mature beyond your years - why do 14 and 15 year old WANT to date someone who is so much older? Anyway, if she were 20 and he were 26, it wouldn't be as much of an issue except that she would still be in college years and he would be involved in a career. I think of life is stages. Her stage and his stage are one crucial step away. She should try to find a mature guy who is in her same stage. She will find so much less strife and life will be so much more enjoyable. Right now, she is trying to stay afloat in a canoe with holes. He is a man, and she is not yet a woman - plain and simple. The loving thing is to let him experience his life, and for him to allow her to experience her life accordingly.