UID calling herself "Mary Anderson/Mary Andrews"

"Mary Anderson/Andrews"  is said to have Killed herself Oct. 9,1996 in a room at the Hotel Vintage Park Seattle,WA. She drank cyanide mixed into Metamucil. We (my mom and I) think maybe she was murdered. Our theory is that perhaps she didn't know the poison was in there. 

                           She checked into the hotel under the Name Mary Anderson and may have also used Andrews as well. "Mary" is said to be between 30-40 years old. She may be older in our opinion. She gave a NYC address that actually has an apartment building across the street. She also gave a NYC phone number that comes back to Queens no where the address. She was clearly familiar with NYC. Who was she really and was she murdered?