Any advice when you have evidence of the executor (my sister) of my mom's estate has been transferring money to herself?

My sister transferred some of my moms money (one month after she put her on hospice against my pleads) labeled college fund for her daughter. She said that mom wanted to help her daughter and my brother's son for college. She said she knew we saved for our kids. She has not provided an accounting or recording keeping of my mom's finances during the almost years she placed her on hospice, after many letters requesting this. My mom's trust allows for accounting at anytime from the executor/POA. My mom's trust is divided up among all her children equally. My mom past away this year, and 2 weeks later my sister started to disburse some of her funds, but I still had not receive an accurate accounting of all of my mom's finances. I have a general idea of what my mom had. She recently has only given us (My belief) some of the accounting from my mom's assets. I have a call to a lawyer to help with this situation. My sister lives close to my mom who was DPOA , and we were at extreme odds in determining the care for my mom. I am a registered nurse. It was my medical opinion and (as does the State of CA) that my mom was being overmedicated and my sister's opinion was quite the opposite. I filed a complaint with the state of CA. As a result, the state did a surprise inspection of her hospice. The State found instances of falsified records, overmedication, and medical care that was inconsistent with her diagnosis and plan of care. My sister ignored my complaints and advice for a course of correction. Not only do I feel vindicated by the States findings and actions , I also feel vindicated that my mom lasted nearly 2 years on hospice. Being a medical professional, I was fully aware of my mom's trajectory and I was at peace with the knowledge that one day my mom was going to pass away. I simply knew that it was not her time, despite my sister's insistence that it was. It was my profound opinion that my sister abused her authority as DPA and the she withheld care that she was capable of providing and that my mom's estate could afford. I eventually started paying for an aide to help her at her assisted living. My other sibling agreed with my sister's assessments, they said it was 3 against one, you lose. You would think in a situation of life and death that everyone would have a vote. My mom was one of a kind, loving, thoughtful, had so many friends, but could be emotional, a little hysterical(because she was scared) and a difficult patient. She was concerned about being a burden on her kids, and losing her independence. She just wanted assurance from us. But my sister took her literally when she would say "throw me in the river." And when she would get compression fractures she would get hysterical with the pain, and then in a couple of weeks, with more pain meds she would be in her groove again. She was misunderstood by my sister and hospice. When people are colorful with their life, they are also dramatic with many of their expressions. That's why she made people feel so special, she showed empathy with her energy. Its been a rough 2 years with lots of miracles in the middle. When the power struggle happened with my sister, my husband said its about the money. He is now proven correct. I just don't know the exact amount, and for how long its been happening. I now have legal rights as a beneficiary of my mom's trust, and I have a lawyer in place. But knowing that she has actually taken funds, puts salt in the wound all over again. Any advice, or experience would be wonderful. I wish I took advantage of this forum earlier, I think I would of done things differently. I also think it took my mom to go from 80 lbs, bedridden, confused, on morphine and Ativan, (put on for hospice for 2 years for COPD, with no oxygen and no prednisone,) to walking, moved to independent living, make her own appointments, arranging rides to dentists, and getting a facial peel, and weighing 121lbs to validate my concern.