Regarding letting folk know that your Mum has diabetes, a good point. She might get admitted muddled due to a high glucose or muddled due to steroids, or if on sulphonylurea, muddled due to low glucose; so important to know, although diabets is so common, it should be considered by medical staff, even if diabetes not known.
There are medic alert bracelets, but they might just get left on the sideboard.
And it would be useful to have a list of medications and other health problems and any adverse drug reactions (like the metformin)
I think that Age UK used to do an older persons "Passport" which was brill - included patient details, next of kin, possibly thoughts on resuscitation etc, diagnoses, drugs etc, but I cannot find this on the net. Might be worth emailing them or walking in to one of their shops
Also, a print out summary from the GP could do the trick
Or, slog away and type it all out yourself.
What to do with the info, cos no good if no one looks at it. So, one copy with your Mum in her handbag; but in some areas, the ambulance men look in the fridge for this info. And one copy with you, and if your Mum has a mobile phone with a contacts list, you could stick your details under ICE (In Case of Emergency), but again, not sure if this is used much.
Having someone like you who is looking out for them ,even at a distance, is invaluable.
Best wishe