THEY arrive wrapped in a protective, hard-as-nails coating. They are used to pretending everything's fine, to shielding themselves from outside curiosity.

The judgements of others can hurt – although not as much as a blow to the stomach or the glowing tip of a cigarette lighter pressed into the leg.

They are the teenage girls who make up the occupants of Aidan House in Nottingham. There are 16 of them, although there is always a waiting list. They have young children or are heavily pregnant when they arrive. And they are, almost always, fleeing domestic violence or a difficult home life.

Gradually, their toughness is broken down. Aidan House radiates warmth.

Assistant manager Jen Dean, a bubbly, jovial woman, shows me the communal kitchen, stacked high with harvest festival donations where, twice a week, staff and girls cook together. "Although it tends to work out it's the staff who do the cooking, while the girls sit around and shout, 'Hurry up! I'm starving!'" she twinkles.

Next door, there's a TV room, with views over a long, light garden, peppered with toys and swings. Then, there's the playroom. Santa visits each year.

There is little to distinguish Aidan House from surrounding properties. It's an ordinary home on an ordinary road – just what these women need.

"They can stay for up to two years," says Jen. "You see the babies walk and talk."

Although the girls move out and move on, they never really leave Aidan House altogether.

"We don't stay in touch with them, they stay in touch with US," says Jen, emphatically. "We see them around all the time – it's lovely. We throw a little party every year."

I'm introduced to Louise*, a soft-voiced girl of 19, who bends her head over her tiny daughter aged 20 weeks. She has her mum's wide, brown eyes and curls. She's a quiet baby, occasionally nuzzling her mum for attention. They make a peaceful picture. But it is a peace hard-won, given Louise's turbulent past. In the eight months Louise has lived at Aidan House, her confidence has steadily risen. When she arrived, heavily pregnant, she was quiet, uncommunicative. It was the third new home in the space of a few months.

Louise had moved up to Sheffield from her Notts home to live with her then boyfriend. It was her first serious relationship.

Her boyfriend smoked weed and his behaviour become increasingly unpredictable and controlling.

If she wanted to go shopping, he wouldn't let her. She was banned from seeing the few friends she had. She wasn't allowed to wear certain clothes. When he went out to work, he would drop her off at his mum's and pick her up on the way home, so he would know exactly where she was all day.

The violence began three months into the relationship. It started in pinches on her body, then bites on her face. Once they had a row about her wearing shorts on a warm day. She thought he had calmed down but, it turned out, he had been sitting with a lighter, waiting for the flame to heat up the metal tip. He then ground it into her leg. She still has the scar.

"He would apologise afterwards," she says. After a while, she stopped believing him. "I would try not to make him flip but then he'd go off about something little anyway."

Five months after moving in with him, Louise discovered she was pregnant. "I was happy but I wasn't happy," is how she puts it. He promised he would stop hitting her. It didn't happen.

The relationship ended after nine months. Some friends from Nottingham called on Louise. They witnessed another fight. "He bit the side of my face and threw me around the bedroom," she says. She was terrified of any damage to her unborn child.

Frightened by what they had seen, her friends returned to Nottingham and told Louise's mum. She raced to Sheffield to rescue her daughter. "She was going mad. She was shouting, 'Where IS he?'" recalls Louise. Luckily for him, he had just popped to the local shop. "She looked at me and said, 'Do you want to come home?' and I said, 'yeah'. She grabbed a bag and walked out."

It was just supposed to be for a little while. But Louise found she couldn't face going back. There wasn't much space at her mum's – her sister had just had a baby – and, for safety reasons, she thought it was best she leave. Her boyfriend came down to Nottingham, looking for her.

Through Gateway, Nottingham City Council's rehousing service for the homeless and vulnerable, Louise was put in touch with Framework, who found a place for her in Aidan House, a service run for women aged 16 to 19 who are pregnant or have children.

Teenagers who regard abusive relationships as normal, as Louise did for a while, present a growing problem.

Research from Bristol University, based on a national survey of young people aged 13 to 17, found that nearly nine out of 10 girls had been in an intimate relationship. Of these, one in six said they had been pressured into sexual intercourse and one in 16 said they had been raped.

Framework reports 189 girls said domestic violence was a major factor in their need for support last year.

Each victim is allocated a support worker.

They help women through the legalities of leaving a partner, a home and, possibly, all their belongings and give them the skills to move on to an independent life.

In Louise's case, she is receiving legal help as she claims her landlord threw out her personal belongings before she had a chance to retrieve them. They included her clothes, a fridge and cooker and more sentimental possessions including a necklace from her grandmother.

Slowly, Louise has started to replace what she's lost. Some new clothes. A mirror. "I buy her toys she can't even use yet," she smiles, looking at her daughter.

Amid the twinkly normality of In The Night Garden she is making plans, looking to the future. She would like to work with homeless people and is planning to do some volunteer work.

She looks at her daughter, still curled angelically in her lap. She says to her baby – or maybe to herself – "It's alright now."

*Not her real name.