On a Friday evening in June while her twin brother ventured out with friends, 19-year-old Brianna Hoover retreated to the silence of her bedroom, where she spent hours dressing up dolls that she's played with since kindergarten.

On evenings like this, no one can reach Brianna. Sitting alone, she determinedly brushed the dolls' hair into tight loops until they resembled the long blonde ponytails that hang past Brianna's shoulders.

"Brianna desperately wants to be out there, experiencing the world like everyone else, but she doesn't have the social skills," said Candy Hoover, who adopted the twins at age 5, and lives in Cambridge. "She feels isolated and depressed."

Like her twin brother, Cory, Brianna was born with fetal alcohol spectrum disorder, a set of conditions affecting children whose mothers drank during pregnancy. Physically, Brianna and Cory resemble other teens their age; cognitively, they have the minds of 8-year-olds, Hoover said.

Hoover was told that a Medicaid waiver would pay for her children to get training in social skills and outings in the community. But five years ago, Isanti County determined that the twins' condition was "not urgent enough," and they were placed on a waiting list.

"It was clear that it would take a serious crisis for them to take their needs seriously," Hoover said.

In the fall of 2010, the crisis came. Cory's disorder was triggering daily rages; almost every one of the eight chairs around the family's kitchen table had been destroyed. Then one night, upset at being asked to take out the garbage, Cory smashed his fist through the kitchen door window. He gashed his forearm and wound up in a nearby psychiatric ward for 72 hours.

A few months later, Cory received a waiver, which pays for individual therapy and outings with his peers. His self-esteem has risen, his tantrums have faded; he now initiates conversation and looks people in the eye, his mother said. Cory's relatives now refer to his life as "before the waiver" and "after the waiver."

Yet Brianna, who is quieter and less prone to tantrums, remains on the waiting list indefinitely. She still needs help brushing her teeth, buttoning her clothes and shaving her legs. Her closest friend is her 7-year-old sister, Jarelyn, who shares Brianna's fondness for dolls, board games and animated shows like the "VeggieTales."

"How long will it take for Brianna to get the kind of services that her brother gets?" Hoover asked. "And how will we ever regain the time that was stolen from her?"