Mum moving from one NHS area to another after stay in hospital

Hi everyone
This is my first time posting so hope I’m in the right section. And apologies in advance if the post is too long.

My mum had a fall on stairs at home in December and broke her ankle. She was in hospital for a few weeks and now is in a rehab hospital. She has a boot on her foot and uses a walker to get around in hospital.

The hospital said she would be fine to go home eventually but she was to scared to with the stairs and given that there is no loo downstairs and that my stepdad (her partner for 30 years) died in November she was already planning on moving nearer to family as did not wish to be alone in the house.

She wanted to find some sheltered housing in the area near family where she lived for 20 years. As she needs a little extra help with the boot and would not be suitable for sheltered housing yet she would first spend 4-6 weeks self funded in a respite care home which has been arranged.

She is being discharged next week but she has an appointment scheduled with the hospital for an X-ray to see if she can take the boot off. I spoke to the consultant’s secretary and explained my mum would be in the new area but she did not have any advice how to get the appointment transferred. She was going to get the doctor to call me as part of a telephone appointment my mum had (I have LPA) but instead they called my mum and told her she must attend the appointment even though it’s three hours away and she wouldn’t be able to travel a 6 hour return journey in a car.

There is a local fracture clinic where she is going but I am not sure how to get her into the system there in time to have an appointment in two weeks. She will have to register with a GP when she gets to new area. Somebody suggested the only way is private but even then would she need to be referred by GP?
If anyone has any experience of this situation or any advice that would be greatly appreciated.