Mrs Messam, 69, added: "We don't like being in the limelight.
"I prefer to be behind the scenes, doing my own work," she said.
After living in Rotorua for 53 years, the Messams plan to sell their home and move to Hamilton to be closer to their family.
As soon as the house sells they will be in a position to move - although it would not be an end to fostering children, she said.
"We're missing out a bit by living here and the family being elsewhere.
"We will be very sad to go.
"We have loved living here, but our house is too big and all the family live elsewhere."
The couple have eight children -five adopted and three of their own - among them Chiefs and All Black flanker Liam Messam.
They began fostering children through Child Youth and Family, and later the Open Home Foundation, after their first adoption.
Most of the fostered children have gone on to be adopted through the Home for Life programme.
The Messams told the Rotorua Daily Post last month they considered their tireless work "a calling" and enjoyed seeing children "coming out of their shell" and "seeing the gloom lifting".