Tricked Out of Inheritance

[Heir Apparent]

My question involves estate planning in the state of: California

Approximately a decade ago, my father-in-law passed away. He died of cancer, and spent his last days on morphine in a hospice. He was a "man with sole and separate property" and, apparently, on the day before his death, signed a will (with an "x") leaving everything to his wife. There was no will before this time. His wife related the story of how she had had to hold his hand so that he could "sign" it with her lawyer present. As the story goes, the lawyer was a little uncomfortable with the procedure, but they went ahead.

A short time after his death, my wife and her sister each received papers to sign forfeiting their interests in the estate. Since they were under the impression that their father had left everything to their mother, this seemed like a formality and was presented as such. Their mother said this needed to be done so that she could get on with the business of changing things into her name, etc. Both daughters signed the papers.

The other day at an elder care seminar, I heard that, in the state of California, if a man with sole and separate property dies without a will, the state's standard allocation of the estate is 1/3 to the surviving spouse, and 2/3 to the children...and a light bulb went off in my head. Their mother had helped their father to "x" a will while he was hopped up on morphine so that she would get everything, knowing that she would only get 1/3 of the estate otherwise.

Sadly, their mother is not an honest woman, and this is very much in keeping with other things that she has done. Given that the will wasn't signed while my wife's father was in his right mind (if it was signed by him at all), is there an opportunity for the daughters to go back an challenge the will?

Thanks for your help!

[Mr. Knowitall]

I'm skeptical that they will have any recourse for an estate that's been closed for ten years, having both voluntarily waived any inheritance at that time and having been aware of the circumstances of the will's execution at that time. They should have the details of their situation reviewed by a probate lawyer.