1. Father was very successful quadriplegic who planned his estate thru a will.
2. Had a tragic accident that put him in a coma for 8 wks r.Then incapacitated by doctors reports thereafter.
3. Mom knew that his will would not pass his estate to her only 1/3 of his wealth
4 She hires a Trust Attorney to prepare a Living Trust to her specifics and as sole client.
5. Without regards. her trust Attorney prepares a Power of Attorney,A petition for Conservarorship .A new Will and Declaration of Living Trust with her as sole Trustee.
6 Athough he had 3 brothers and 5 sister all in Calif. He chose his brother in law to be successor trustee and Conservator/POA
7Quit claimed all property and investments to trust with an X witnessed by 2 of Moms friends.
8. It appeared all assets would pass to his 2 adopted children "child's trust"
9.Mother was Trustee of Living,Exemption,Survivor.
10.Through a will she 3 irrevocable trust to successor trust then passied it to her famil
This is quite evidently a highly fact-specific situation, which is not suitable for this forum, which is for questions of a general information.
In any event, there are critical facts missing from your narrative that could change the answer 180 degrees. Your best bet is to schedule a consultation with a will contest attorney.