In an exclusive statement to PEOPLE on Friday via her attorney, Tanya Callau is claiming that the Growing Pains actor's sons — Brennan Thicke and chart-topping singer, Robin Thicke — previously propositioned her about turning Alan's Carpinteria, California, ranch into a marijuana plantation, and filed Tuesday's petition against her out of retaliation when she declined.
"Since Alan died, his sons have been haranguing her to let them turn America's dad's homestead into a massive pot plantation," Callau's attorney, Adam F. Streisand, writes in a statement to PEOPLE. "When she said no, they filed this bogus lawsuit and smeared her in the tabloids."
The statement concludes: "They're just trying to bully a woman whose only crime is loving their father with everything she had for 17 years."
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According to court documents obtained by PEOPLE and filed Tuesday in L.A. County Superior Court, Brennan and Robin claim in the petition that Callau is now alleging that the prenuptial agreement she signed ahead of marrying Alan in 2005 is invalid.
Prior to his death, Brennan and Robin were named co-trustees of their father's living trust if his brother, Todd Thicke, declined to take on the responsibility (Todd did decline). In February 2016, the most recent iteration of Alan's trust was signed; the two brothers allege that Callau did not make any complaints about the estate or prenup at that time, according to the docs.
According to the documents, Alan, who passed away unexpectedly on Dec. 13 at 69 years old after suffering a heart attack while playing hockey with his youngest son, Carter, left each of his sons "(in equal shares): ownership of the Carpinteria, California ranch that he bought in 1989 and desired to keep in his family forever (the "Ranch"), 75 percent of his personal effects, and 60 percent of his remaining estate."
Callau was left "all of the Ranch's furnishings, 25 percent of his personal effects, a $500,000 life insurance policy, all of his death benefits from pensions and union memberships … and 40 percent share of his remaining estate. Alan also provided that Tanya may live in the Ranch after his death so long as she maintains the property and expenses."
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But in the time since her husband passed away, Callau is allegedly now claiming that the prenuptial agreement she signed over 10 years ago is invalid. "Nonetheless, despite Alan's generous benefits and careful planning Tanya demands more. Tanya insists the Prenuptial Agreement that she entered into before marrying Alan is invalid," the documents state.
Attorney Alex Weingarten writes in the petition, "Now that Alan is dead, Tanya claims there are numerous problems with the Trust and the Prenuptial Agreement," which includes Callau's alleged claims that "she had to forego opportunities to pursue and advance her own career in order to support Alan and be his companion and partner, including raising Carter."
Callau also allegedly claims she has "rights of reimbursement with respect to improvements to the Ranch."
However, Streisand previously told PEOPLE in a statement: "Tanya Thicke has never threatened to take private family matters public and she never has. It is clear that Alan's sons have chosen this distasteful public smear tactic to bully Tanya, by stirring up the tabloid media, filing a bogus lawsuit, and refusing family mediation. Tanya is still grieving the death of her beloved husband and out of respect for Alan's memory intends to handle his sons' false statements privately."
A rep for the Thicke brothers did not respond to PEOPLE's request for comment.