The Duchess has compared to two events, claiming she is giving away two children this year.
She wrote on the Evening Standard: “Children in Crisis is merging with Street Child, a charity which the Evening Standard has brilliantly supported.
“I met Tom Dannatt and his team at Street Child and we had so much in common with them.
“I see it a bit like Eugenie getting married later this year.
“She’s 28, and when your children get to that age, you let them do their thing.”
Fergie then reflects on how the charity has become her "third child."
She wrote: “Children in Crisis has been like a third child to me over the past 25 years."
“Now it’s time to let it do something new and better.
“We agreed with Street Child that together we can pack a bigger punch," she concluded.