I would like to have my PA on the video call (PIP consultation) with me. She will not be in the room with me, as she'll access it from her home. Do I need to give notice to DWP that she'll be attending? Do I just give her the weblink they've sent me, and she logs in giving my name rather than hers?
You are entitled to have someone with you. You should check with the assessment services beforehand how this can be done with someone in a different location. There should be a telephone number on your appointment letter.
You want to know - so there is no problem with her logging on. I am not an expert in these things, but if you have logged in already, the system may not let another person log in with the same link trying to use your name or even a different one.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems