A felony can be reduced to a misdemeanor, or even dismissed and refilled as a misdemeanor. But if one pleads to a felony, it never "drops down" to a misdemeanor.
Well, either it can (and did) or your sister has a misdemeanor that she didn't tell you about.
I suggest that you ask her.
Still, I hope that I have been helpful in answering your question.
Larry Lex JohnstonCriminal Defense AttorneyHurst, TX ·
Without looking at the case and, more importantly, what you are looking at, nobody can tell you what you are really wanting to know. A felony conviction can never become a misdemeanor. But, there is always the possibility that she THOUGHT she had a felony and really didn't.