Roommates with your bestfriend

Yesterday my best friend asked me about being her roommate in the future. We have a great relationship and I've been knowing her for 14 years and we are very open with each other so far we have not had any issues. I'm not sure that becoming her roommate is a good decision because my mom told me her experience with that and her and her friend are no longer friends. Also and old friend of mines mother told me that it sometimes does not end well. Has anyone had bad experiences with that? Or good ones?