Ashleigh Hall was a "typical teenager" who dropped her clothes on her bedroom floor and spent hours chatting to friends online, her mother said.
She spent her pocket money on top-up cards for her mobile phone so she could text them too, Andrea Hall said in the aftermath of her death.
The single mother, 39, of Darlington, said the 17-year-old was her friend as well as her daughter.
She said: "She would have been 18 just after Christmas, she had her full life in front of her."
Ashleigh helped bring up her sisters Olivia, six, Ellie, four, and Evie, aged one, and was studying to be a nursery nurse.
Ms Hall said: "Ashleigh was my rock. We were on our own for 11 years because I had my three other daughters late.
"Because of that she was also my friend as well as my daughter.
"She helped me constantly with the others. She baby-sat, ironed, changed nappies, she did everything I asked her to.
"She fed, washed and bathed them because she had a loving nature.
"I would give her a little bit of pocket money for helping round the house and she used every penny to top up her phone to chat to her friends.
"She was always talking and texting and on her computer.
"As soon as she got in from college she would be on the computer using MSN to talk to her friends even though she had been with them all day."
Ashleigh, a former Brownie and Guide, used to play her favourite music loud and dropped her clothes on the floor.
Ms Hall said: "She just took her clothes off and left them on the floor thinking it was my job to pick them up."
The teenager's bedroom was dominated by pink, with a Playboy bunny duvet cover and curtains, and photos of friends and family all over the walls.
Ashleigh, an animal lover, did not have a boyfriend, her mother said.
"Ashleigh wasn't a bad kid. She wasn't naughty. She made one mistake and has paid for it with her life," she said.