Hatcher and Emerson visited a boarding school where the students hit it off with the California girl.
"They loved my daughter," Hatcher, one of the stars of ABC's Desperate Housewives, told The Associated Press in a phone interview from Tanzania.
The 43-year-old actress recalled a moment when a little girl in the back of a classroom raised her hand during a question-and-answer session, but "got really shy" and ran up to whisper a question in her daughter's ear.
"We talked about math. We joked. They would say, `What subjects do you like in school? What's your hardest subject? What do you like? What do you do? What's your favourite thing to do?' We talked about sports. We talked about who likes science, who likes math, who doesn't like math, `fractions are hard,' stuff like that," she said.
Hatcher said her daughter brought letters and drawings from her classmates to kick off a pen-pal exchange with at least 40 children at the boarding school.
"She's been more excited about that, I think, than seeing the giraffes and the hippos" on their two-week African trip, Hatcher said.
Hatcher raised more than $US35,000 ($NZ46,585) in donations and supplies from individuals and companies for AmericaShare, which primarily provides education, food and housing to children and adults affected by poverty and HIV/Aids in Nairobi.
She presented a cheque to the organisation when she arrived in Kenya.
The 22-year-old nonprofit organisation has a program that sponsors poor children, many of them orphaned, and places them in boarding schools in Nairobi.
Hatcher also visited an orphanage in Nairobi's Mukuru slum.
She said her goal is to raise money to improve conditions in such communities as well as the lives of families and children.
"I was sitting just surrounded by kids and I was saying, `What do you like to do? What's your favourite thing to do during the day?' And I think the one kid thought I said, `What's your favourite day?' Because he said, `My favourite day is this day,"' Hatcher said.
