Trek Marlin do I need adapter

I am planning to put a Bafang system (Probably 1000w) on a new Trek Marlin 5 for my girlfriend. I am wondering if the Bafang system fits the bottom bracket "as is" or if I will need an adapter. Also, from looking at photos, I assume that the battery will not fit in the Marlin 5 woman's frame with the bend in the tube, especially since it will be a size small frame. Can anyone confirm that is true? Thanks