DLA home visit to check ID

I recently helped a client to apply for DLA for her daughter who is 22, lives at home and suffers from PTSD, severe depression and anxiety. She also has Borderline Personality Disorder and is a registered methadone user. We mentioned the drug use and methadone dosage but made it clear that this is simply background rather than a main reason for claiming. The daughter refuses/is incapable of engaging with services (although luckily we have a prior psych report as evidence) and her mum wants to be her associate and get the money paid to her.

DLA phoned and said they wanted to come round. She assumed they were doing the medical assessment at home, but when the letter arrived, they said they needed to check ID and there is no mention of medical assessment. I understand wanting to check they are who they saw they are, but can they still do the medical assessment while they are there? Is there anything they should do?

This sounds like it could be a visit regarding the Mother becoming the daughters appointee for her benefits. Has this been requested?