It's hard to get a nappy as absorbant as a BBH but trimmer I think.

Do you use any AIO's at all? They aren't as stiff as a BBH and cover. Ruby spends most of the time in itti bittis during the day as well as a few other AIO's. For fitteds I use very baby and itti bitti boos.
She has really only started rolling all the time now with a nappy on. She was the same in that she was over in a flash with a nude bum but didn't do much with one on. Till this week and she's on the tum all the time but she's got a month on your little one.
Maybe Louisa needs a tad more time to get into it also