Short and heartfelt
“Thank you for your kind words, cards and flowers, and for the love and support you have shown us.”
“Your kindness and sympathy at this sad time have been a great comfort to us all.”
“Thank you for being with us to celebrate a life so well lived.”
Signing off
Most families sign from the closest relatives, such as “With love from Mary, Paul and Claire”, or simply “From all the family”.