The 22-year-old has been a shoulder to cry on for Sandford following her split from McFly's Dougie Poynter and they are now ready to take their friendship to the next level, The Mirror claims.
A source told the newspaper: "He has the hots for her, that's for sure. It's still early days but there's so much chemistry between them.
"Frankie has been so upset and went on a girlie holiday with Rochelle, Vanessa and Una from The Saturdays to get over the split. She had moved in with Dougie and she really believed that their romance was for keeps."
The insider added: "Work commitments tore Frankie and Dougie apart. Aston has been so sweet by offering her support.
"She's now looking for love. She wants to get back out there and find her Mr Right."
Merrygold's JLS bandmate Marvin Humes recently confirmed that he is dating Saturdays member Rochelle Wiseman.