The mother of a teenage girl who was found stabbed to death said she had experienced "complete emptiness and disbelief" since losing her daughter.
Lucy McHugh, 13, was found dead in woodland near Southampton Sports Centre in July.
Her mother Stacey White said she would keep her memory alive and stop her killer from destroying anyone else.
An "I Love Lucy Day" to raise funds for a memorial garden will take place on Saturday.
Ms White said her daughter was "always full of smiles".
"The biggest, smiling person in our lives has been taken and she's never going to come back," she said.
Lucy was a keen music and sports fan, who had been involved in gymnastics, trampolining and majorettes.
But her mother said she was also a girl with a mind set on a particular career path.
"She had come to a very strong decision that she wanted to study law and she then wanted that to lead her to moving to America," Ms White said.
"And then becoming a pro bono lawyer to help people who couldn't afford to help themselves."
Describing her life since Lucy passed away, she said: "It's a complete emptiness overcoming you all at once. Your whole word falling apart.
"People can pick up text books, they can read them until they're blue in the face. It is not as it is written. It is such a more complex layer of sorrow and heartache and just destruction."
However she said she had been forced to stay strong and "survive" for her other three children.
"You either allow it to destroy you or you fight. I'll fight. I won't let Lucy's memories die. I won't let her be forgotten. I won't let this destroy any more people than what it has already.
"I won't let whoever has done this destroy anybody else."
Hampshire Constabulary said officers were following a "new line of inquiry" following a new search in part of the sports centre ground earlier this month which had not previously been targeted.
Lucy was last seen walking along Coxford Road, past a Tesco Express store, at 09:30 BST on 25 July.
Her body was found near the sports centre early the next day, nearly two miles from her home.
Stephen-Alan Nicholson was jailed for 14 months in August after he admitted failing to comply with an order under the Regulation of Investigatory Powers Act, requiring him to disclose his Facebook password to detectives investigating Lucy's murder.
The I Love Lucy Day event, which will also raise money for charities that support bereaved parents, will take place in Mansel Park in Southampton.