The money was raised for the Sunni Mae Trust via HMV stores through the sale of charity single Tiny Dancer.
However, there had been fears that invoices for amounts totalling €27,000 sent to the music store last week would not now be paid.
Receivers have been appointed to the Irish branches and all stores around Ireland are currently closed.
Lily-Mae's mum Judith Sibley, speaking from her daughter's hospital bed in an isolation unit at Crumlin Children's Hospital, said: "People went out of their way to buy these CDs because it was for Lily-Mae and the Neuroblastoma charity.
"I just have to keep my fingers crossed because it would be devastating if the funds disappeared. I have to believe that won't happen."
Producer of the charity single Stephen Macken said he had been contacted by the receiver, David Carson, who assured him that they would prioritise the charity.
"He rang me on Wednesday, it was one of the first calls he made. He said he was acutely aware of our situation and would prioritise it," he explained.
Mr Macken said the main concern was proving that the charity had an agreement with HMV as a Trust.