I was looking at that as well, and wondered how an identification could be made. There is virtually no information other than her first and last name in the announcements, plus the fact that both were placed by a Matthew Maitland. The Burke's I have lists her with only two children, John and Camilla, but I know there might be more recent editions. Is Matthew another child?
"Carina Maitland died on 22nd September, 2018. Beloved wife, mother, grandmother, sister and friend. Private family funeral. Memorial service to be advised."
"Carina Maitland. A Memorial Service will be held at Chelsea Old Church, 64 Cheyne Walk, Chelsea, London SW3 5LT on Tuesday, 29th January, 2019 at 5:30pm."