The Daily Star claims that Shirley (Linda Henry) will find the photo frame that Ben Mitchell (Joshua Pascoe) hit Heather (Cheryl Fergison) over the head with before she died while browsing in a charity shop.
Shirley promptly goes to the police with news of her discovery, determined for Heather's killer to face the law.
It has also been reported that Shirley will ask long-term partner Phil (Steve McFadden) to marry her in a further bid to keep an eye on both him and son Ben.
"Maybe she thinks keeping him close will put her in the perfect position to spy on him and Ben," a production insider told the paper. "She's not going to give up until she's brought Heather's killer to justice."
An EastEnders spokesman declined to comment on the rumours, saying: "We never comment on future storylines as we don't want to spoil the surprise for viewers."
It has been confirmed that Pascoe will depart Albert Square, although no further details surrounding Ben's exit have been revealed.