It is really helpful. And good she can get a hamster mix that way as then she'll get all the nutrients she needs. You can actually buy porridge as oatmeal - in various grades of size - the smallest oatmeal is already like crushed oats, which might help.
This kind of thing - health food shops probably sell it, but Mornflake sell different grades of oatmeal in supermarkets sometimes as well.
https://www.amazon.co.uk/Buy-Whole-F...ywords=oatmeal
I think I'll get some myself! It makes a very smooth porridge. Although I think the medium might be better for porridge - the fine is almost flour.