Dear Judy,
It is awful to be told (or realise) that one's loved one is no longer safe at home, but please, please be relieved that she will now be looked after constantly and you will worry no more about what might happen.
The day I took my parents into their care home I had breakfast with them before their left their home they had been in for 40 years. The bread in the toaster was a bit slow for Mum's liking so she got a knife to prise the toast out, fortunately I stopped her in time! If I ever have any doubts about whether I did the right thing, I always think of the "toaster incident". Maybe there has been something in your life you can recall if you ever have any doubts.
Good luck, I hope you find somewhere nice for her.