I found this bit somewhat bizarre – and it was really hard to find out what you were meant to do but worked it out in the end –
You have power of attorney – you are authorised to act on her behalf so when you feel it is appropriate you can do so. Nothing needs to happen, you don’t need to report that you’re doing it or tell anyone. It doesn’t mean you have to act on her behalf for everything. She can continue to do stuff alongside you.
Depending on what the organisation is they might require you to fill in some forms and usually want to see the PoA doc (banks can be quite heavy on admin on this) but others you just show them – that should b enough for the estate agent. (they usually take a copy to record why they’ve let you act).
First thing you should do is go to a solicitor and get some certified copies of it made – which the solicitor should sign and stamp on EVERY page. You really don’t want your only copy going missing in the post, or some company taking ages to post it back to you.