They just said that whilst most grow out of it some don't.
She's fine if you're with her and fine when she's out thank god, the vet said she knows of some who have to be mussled when they're out as well poor things.
Less than a week after I got her she almost died. They had to operate to remove a 10cm piece of fabric from her intestines. Best they could guess was it had been there at least 2 weeks as it had started festering.
She's eaten countless shoes and various items of clothing, every bed she's ever had plus it's stuffing (I've had to resort to just a blanket as she passes pieces of that quite easily), destroyed the arm of a sofa in half an hour, pulled the side of the wooden fire place off, ripped up and eaten a metre length of beading from the floor (thank god she spat the nails out), pulled a floor to ceiling horizontal blind down and wrecked it, pulled all the bedding off, ate my razor (again luckily, it had a blade cover on) and eaten a whole lead.
I've got an extra tall gate on the kitchen but she just barges it until it forces open.
The crate is obviously the best thing for her, as well as keeping her safe it really calms her. From day one she's just happily walked into it and curled up to sleep.
Like you though, it would be really nice to be able to go out for more than a couple of hours!