The former Las Vegas star visited the country as an ambassador for U.S.-based non-profit Population Services International.
During her trip, she helped teach prostitutes how to use condoms and spent time with sex workers and their children.
Sims now plans to sponsor the schooling of three kids sold into domestic slavery after witnessing the horrific conditions they live in - and she's calling on others to follow suit.
She tells the New York Post, "It is heartbreaking to see so many young girls and boys suffering. I spent some time visiting brothels and showing prostitutes how to use condoms to prevent the spread of AIDS.
"I met one woman who has three children and prostitution is the only thing she can do to feed them. I met children sold by their families into domestic slavery, who are abused and worked around the clock. It costs just $200 (£125) to get them into school for a year, and would make so much difference because they have no light in their lives."