My Grandmother Gave Will To Her One Daughter Of Full Property.

Hi Sir, we are total 13 people in share of one house property. My grandmother's daughter took will from grand mother that she is the only owner of full property. Grandmother gave will at the age of 83 and we all 13 people does not know who all are in sharing in property. Will is done in 2014 and after my grandmother passed away her daughter sent to us this will saying she is the owner of this property. Is this will is velid?