I am not sure what you mean, how do you not know if it’s engagement? If it’s just a ring, it means nothing. I have very expensive jewelry from my ex but we aren’t together and we’re never engaged (although we were together for over 8 years), I still own and wear it, we parted amicably (I left but there was no drama) and I am married to someone else now. It’s jusg jewelry. What I am trying to say is just buying her a ring doesn’t mean anything in terms of commitment