"It's the No. 1 sin of adoptive parents, is the overindulgence of commercial and material benefits," she said. "We're not here to entertain children. We're here to give you a work ethic and teach you how to work and how to be responsible. And how important the family is, your connections with people."
Child psychologists say Sterkel is on to something, but it can take years to teach respect, set limits and build self-esteem.
In the week that the Mulligan children spent at the camp, some progress was made. For Tanya and Mike Mulligan, there's a sense of camaraderie with other parents.
"We're not alone," Mike Mulligan said. "We thought for the longest time -- other children are experiencing the same behaviors. The parents are at different breaking points. And the camp is really kind of a catch-all."
Margarita had a breakthrough at camp, telling "20/20" that in Russia, she had been the favored daughter, but in America she feels like she plays second fiddle to Elena.
"She's an extremely hurt kid," Sterkel said. "She has a lot of pain inside of her and she doesn't want you to see it."
Margarita says she thinks her parents wanted to buy her love.
"They always take us shopping. And, if they buy us things, they think that we like them because they're buying things for us," she said.
At the end of the week, she had a surprise for her mother -- a hug.
"I almost didn't know how to react," Tanya Mulligan said. "She actually reached for me and I was very, very surprised. I was very happy that for once she was reaching for me. Just once, it felt very good."
The Mulligans are understandably afraid to put too much stock in such a moment, but say they're "cautiously optimistic."
"There are millions of children out there that need parents," Mike Mulligan said. "Every child deserves to have a loving home. I think the message really that we're trying to send is 'be prepared.'"
Click here for more information about Nina Hilt.
Click here for more information about Joyce Sterkel's Ranch for Kids.