Will/Living Trust

My Grandfather recently passed away. I am not sure if he has a will or a Trust. My mother and I requested a copy, and My aunt (who says she is in charge of it) said she didn't have time to get us a copy. I might also be named on it as secondary in charge, but not sure. I know we have to request it in writing via certified mail, but how long does she have to respond? Please tell me what I should do.Thank you in advance for your help.