The “railings of love” were the idea of the little girl’s family, who say they have been staggered by the response they have received.
“I am so in awe of them and continually find myself down there looking at them whilst on my daily exercise,” said Thalia’s grandma Christine Johnson.
“It's actually breathtaking to just stand back and see other people chatting about them and how moved they are by them. They have brought a smile and a tear to so many.”
Five-year-old Thalia, who had restrictive cardiomyopathy and was awaiting a heart and lung transplant, captured hearts across Scarborough and beyond with her beaming smile and generous spirit.
After her death in August last year, her family launched the Thalia-Beau Foundation to raise money to help other families caring for very ill children.
They have been asking people to nominate hearts for loved ones in return for a donation to the foundation.
They were hoping to reach 50 hearts but have been inundated with requests and have strung more than 300.
Donations have been coming from as far afield as Australia and America, and the project has collected nearly £800.
“We've displayed hearts on the Marine Drive railings before, for organ donation awareness, but only a handful,” said Christine.
“When thinking of ideas for Valentine's, those hearts came into my head and I thought let's fill those railings with beautiful little hearts, let's fill them with love.
“Everybody knows how much the north side means to us. Thalia lived her life down there. She loved the sea, the castle, her pal Freddie and of course her beloved beach chalet.
“Nothing can mend our broken hearts but to know we can give a smile, some comfort and a warm heart to others really does mean the world to us.”
Every heart has been hand-painted and written by Thalia's cousin, Charlotte.
The money raised will boost the foundation’s work creating care packages for families with children in hospitals including in Scarborough and Leeds.
For more information or to donate, visit https://www.thethaliabeaufoundation.co.uk.