The Clueless star passed away in December 2009 after suffering a cardiac arrest at the Los Angeles home she shared with husband Simon Monjack. The filmmaker also died at the property five months later, with the cause of death in both cases found to be pneumonia and anaemia.
Sharon Murphy has now sued law firm Steiner & Libo for advising her to take a settlement regarding concerns about the condition of the property, which is believed to have harboured a "toxic mould" that contributed to the couple's deaths.
In legal papers obtained by E!, Sharon's new attorneys have argued that Steiner & Libo - who represented her and the building's operators The Nina Bow Trust in a legal battle against contractors - should have concluded that Murphy and Monjack passed away due to "complications from conditions associated with [the] defective construction" of the house.
She alleges that lawyers "had a duty to advise and/or inform Plaintiff that she may have had a wrongful death claim", which they apparently failed to do. The suit was settled for an undisclosed sum in January 2009 "with prejudice", meaning that it could not be refiled.
Sharon is seeking damages and court costs on charges of legal malpractice, breach of contract and breach of fiduciary duty.
She declared in December 2010 that coping with the death of her daughter is still a daily "challenge".
The house where the couple died was put up for auction in January.