You can have a quiet word with her doctor - he/she will not comment (and that is right at this stage), however they will keep a "look out". A moment will come at some point if she needs your support......it is getting this onto the table when appropriate.
So such follows on from this, not leastcare resources, financing, power of attorney, wills, driving, insurance etc....
My "incident" today with my mother almost bordered on the farcical - thank you, her Building Soc teller, as we were taking money out one minute and then re-depositing it as we couldn't remember what we needed it for - and had made an exceptional trip into town to resolve....