My grandmother became POA when my Mom was sick. Now Mom's passed and my grandmother will not tell us anything. Any advice?

My Mom passed on the 17th. She was sick for years. My grandmother became poa while my mother was sick, she refused to have fun or inform kids. After she pasted my grandma refused to let ne of her children know wat was goin on didn't let us get n e belongings refused to hav a showin so other friends and family could not say their good byes. No nothin at all no pics no nothin at all. Is there n e thing at all I can do to find out wats goin on wit my mother her pics and sentimental things to us? My grandmother has been gone for years now and I don't understand how she just came up while my mother was already sic and took power of attorney from me and locked me and my 2 brothers completely out of our mothers medical affairs