By Jill Smolowe

05/17/2013 at 01:00 PM EDT

From left: Amanda Berry, Gina DeJesus and Michelle Knight

Reuters/Landov (3)

Though each was young and vulnerable, all three of Ariel Castro‘s alleged kidnap victims came armed with strengths that would help them endure the years of horror ahead.

Gina Dejesus, 14, had the buoyancy and affection of a well-loved child who knew that home and family were worth fighting for. Strong-willed Amanda Berry, 16, was, to her family, “the glue that kept everyone calm,” says childhood friend Lisha Jacome, who lived briefly in the Berry home. A frequent babysitter for her sister’s two daughters, Berry had child-care skills when she bore Castro’s child in 2007. For that birth Castro designated his oldest captive, Michelle Knight, as midwife – and threatened to kill her if the baby died. The mother of a 2-year-old son when she was kidnapped at age 21, Knight not only had experienced childbirth, she had helped perform a delivery of the family dog’s puppies as a kid.

Says her mother, Barbara Knight: “She watched, she learned.”

For now, the three women are talking to no one but family members about what went on behind the sealed doors and windows at 2207 Seymour Ave. in Cleveland. Through an attorney they pleaded for privacy and stated that the details of their ordeal will remain closely guarded “until Castro’s criminal case is over.” But even as they adjusted to starkly different welcomes, a picture began to emerge of the deep bonds they developed during captivity.

“They are like sisters,” says Matt Zone, a city councilman close to the DeJesus family. “They were a family.” That caring was on display last week when Gina visited Michelle in the hospital. Michelle’s brother Freddie Knight, who was in the room, describes the get-together as that of “two best friends.” A DeJesus family friend says that Gina’s parents, concerned about Michelle’s uncertain future, may “take her into their house.”

During their time locked – and sometimes chained – inside Castro’s squalid 1,400-sq.-ft house, Gina and Michelle spent the most time together. They occupied the upper floor; Amanda and her child Jocelyn were kept separately.

“Amanda was kind of by herself because she had this horrible man’s daughter,” says a source close to the investigation. “They all bonded when they could. But I do know the other two girls had the stronger bond than Amanda. The other two leaned on each other, and Amanda had the daughter to lean on. All three would look out for each other.” This source says Amanda was held apart “because he took [Jocelyn] out. That’s the only thing he did right.”

Now as Castro, 52, sits in a Cleveland jail cell, held on $8 million bond, facing charges of rape and kidnapping, he is very much alone. His two brothers, who were initially arrested, then released after investigators determined they had no involvement in the kidnappings, denounced Ariel on CNN.

“Monster, hateful,” Onil Castro, 51, said. “I hope he rots in jail.” “If I knew that my brother was doing this,” Pedro Castro, 54, said, “I would call the cops.”

So how did Ariel hide the sordid goings-on when his sibs dropped by? “He would let me in not past the kitchen,” Pedro said. Instead he quickly handed off alcohol and food, then guided Pedro back out to the stoop. If the captives made any noises, Pedro said, they were masked by the radio.