Smaller caliber is not always the answer. Maybe a larger gun would be more helpful. I would not suggest a 380 or smaller to anyone.
Let her pick. Whatever she shoots best. Everyone is different. No one can answer that, but her.
She needs technique first and a mindset.
The book along with Jason's advice. She can look for her own (with you) and draw her own conclusions.
Sáncte Míchael Archángele, defénde nos in proélio, cóntra nequítiam et insídias diáboli ésto præsídium. Ímperet ílli Déus, súpplices deprecámur: tuque, prínceps milítiæ cæléstis, Sátanam aliósque spíritus malígnos, qui ad perditiónem animárum pervagántur in múndo, divína virtúte, in inférnum detrúde. Ámen