Tiffany Wilkinson, 17, from Ashton, said she was so touched by media reports about Poppy-Mai Barnard, from Blackburn, that she felt compelled to help.
The 16-month-old was diagnosed with a rare fatal brain tumour in February and died eight weeks later.
Now a fundraising campaign is underway in her memory to provide a sanctuary for other sick children in her honour.
Tiffany, who works as a receptionist and as a hotel housekeeper, said even though she didn’t know the family, she wanted to hold a charity event in Preston.
She said: “I was so touched by the story. It was so upsetting to see something like that and I knew I’d love to do something to help.
“There’s been a lot of organising and still more to do, but it should be a brilliant day with things for the whole family to enjoy.
“I’ve been in touch with Poppy-Mai’s family and they’re pleased and one of them might be able to attend.”
The event, featuring DJs, a bouncy castle, football games, stocks and sponges, raffles with an array of vouchers and bingo takes place on Sunday, June 19 from 12.30pm to 4.30pm at Farrington Park Community Centre, Thirlmere Road, Preston.