Should this will be probated? Is there potential fraud? Am I entitled to an accounting of my mother's estate? What happened to all of her assets?

Dec 2020, I found copy of mother's will; 2012 mother died in Cambridge living in house she and my father(dec.,1985) purchased in 1968. My brother apparently took or sold everything she was possessed of her house, money, precious jewelry, antique furniture,furs,accounts, Analog Devices stock, other valuables, Cambridge City pension, insurance, her portion of proceeds from the sale of her father's (3 )Cambridge properties that my mother, 3 sisters and two brothers (all age 70+) litigated 2 estates for 13 years driven by my brother, a NY attorney. I found online two deeds on mother's residence filed within two weeks of each other conveying the property to her and my brother 1) tenants in common, 2) joint tenancy with rights of surviovorship notarized by a family friend. Late uncle alledged my brother brought all of her money to NY "to invest it". To my knowledge, there was no probate of her will or administration of her estate since I never received any such notification.