The 25-year-old journalist and socialite was found dead in her home on April 7, though authorities initially described her death as "unexplained and sudden."
If the reports are true, Geldof's death would be a sad echo of her mother's own passing in 2000. Paula Yates, a British TV presenter, died of a heroin overdose in 2000.
Despite a previous reputation as a party girl, Geldof seemed to have settled into a quiet family life with her husband, Thomas Cohen, and two young sons.
In a column for a British parenting magazine, published posthumously, Geldof wrote that motherhood had saved her from a life of "wanton wanderlust."
"Now, with a new-found group of mummy mates, both locally and online -- all with the exact same struggles and issues, and who don’t question if my child flings food at their hair or care if there’s a screaming fit in the middle of street -- I’m happier than ever," Geldof wrote. "I’ve achieved a sort of perfect balance. Right now life is good. And being a mum is the best part of it."
In a final post to her Instagram account, which has since been deactivated, Geldof shared a photo of herself with her mother.