Some ragdolls do need alot of grooming it just depends on the coat type. All ragdolls should be groomed at least once a week no matter what. Most of them don't have coats that matt really bad like Persians but they do still matt if not groomed.If you think your mum could cope with that then I would say a ragdoll is a brill choice most ragdolls do grow to a large size and if they are from the American lines they do tend to be larger but not all are large though like humans you get some big and some small just depends really.
Most ragdolls are very loving and very trusting and that is why they should never ever be let out on there own.
I doubt that your mum will get a ragdoll kitten from a rescue but if she would like a slightly older one then get her to fill in this on line form
UKRCC Adoption Form.
We do get other breeds as well. if we have anything suitable in we will get back to you.
We do not re home any of our cats from the 1st Dec and usually don't until the end of Jan as Christmas is not an ideal time to re home a cat.
Has your mother also thought about a short haired breed like the BSH? there would be very little grooming with them and they grow quite big too.
Umm I short haired Ragdoll not seen one before myself
Good luck