Dear Simon,
What an epitaph:
So after all the ups and downs, this is the way to remember her! I am so glad for her. Wouldn't she be proud and happy to read that from you about her!
It looks as if she lived to a fine age, despite the dementia - and obviously you played a large role in making things as safe and comfortable as possible during her illness.
Please accept my sincere sympathy, but be proud of all you have achieved. BE