I guess you have your answer by now, lol, socialization and training classes.

I don't know the folks who now own Lexie. As an adult, she will be a strong dog. This is why those 2 things are so important. Lexie will easily pull a petite person off their feet as she charges to meet another dog, or a person (even if she is running to meet them happily, and not aggressively). So the 2 things combined will help with this. Lexie will learn to meet others politely, and not to pull (one can only hope ha haa), as well as to obey when she hears a command to leave it.

Not knowing her background makes these 2 things even more important, as you don't know the breeding history. Many pitties today are bred to be loving family pets, but you can't be sure with this girl. Also, she may have some trauma left over from her first months, which sound less than ideal.

I think a breed specific forum is always a great idea. Behavior, health issues, not too many grooming issues with pitties, lol, it all gets covered and there is always someone who had to cope with it before you. Sharing that experience is quite helpful.

Tell your friends Good luck with her!