Hello Bettyboo
Yes it does seem a low score but when my husband was tested, his test had a maximum score of 30 so your mum might have had a different test.
This is why it is best to ask the doctor who tested your mum , but if you have difficulty contacting him/her, perhaps you could contact the department where your mum had the test.
I'm pleased you found talking point at the start of your mum's illness. It won't make the illness go away but it should help you to be able to communicate with people in similar positions.