Yes, always and only F/T, and I warm them up with warm water just before feeding. She's still eating small adult mice, but she's probably going to outgrow them in a couple weeks and I'm going to try her on rat pups. She's a fierce eater, so I'm not concerned about her eating in general, just want to make sure the backwards thing is okay! Admittedly my husbandry needs a little tweaking - I keep the house very cold, so keeping their enclosures warm enough is a challenge but I've mostly got it handled - but neither of my girls has any issues that I can see. I'm slowly but surely adjusting my husbandry to be more ideal, as I can afford it.
Tonks is just weird - when I got her, she was the one baby BP there that wasn't in a hide, which was what made me notice her. She was sitting around out in the open, just like she still does, so I think being out and about is just in her nature. Right now she's just finished her 5th lap around her tank, stopping for a drink of water each time she passes her water dish, and now she's digging a hole in her substrate. She is a very strange baby, but has a fun personality now that we've handled most of the fear out of her. The other day I had her at my niece's house doing her schoolwork, and Tonks curled up on her keyboard and stayed there most of the day while Niece worked! (Both of my BP's loooove my niece, she's 7 and a little animal whisperer. Ana Gwyn practically jumped out of my hands and onto Niece's neck the last time we saw her! I'm pretty sure she'll steal the heart of my new baby false ghost bullsnake when he gets here next week, too.)
Try thawing slowly in the snake room then when feeding give just the head a good blast with a hairdryer- offer instantly whilst still warm ..