You need to be an established heel, or have a better turn for some cheap insults to actually garner heat.
Charlotte isn’t nearly over enough as a face to make a Becky turn stick, and there really isn’t another face she could beat up to get it either.
Plus the timing is completely wrong. Becky is more over right now then she might have ever been. This is not when you turn someone.
Honestly this kind of booking screams sabotage. They want to keep pushing Charlotte in a build towards Ronda, but Becky is getting too over for it to work. They don’t want to outright bury her, but they need to cool her off so “bam” ill advised heel turn.