Did you at least let her know that she can go marry anyone who she thinks is also right for her. It may sound bad but at least you give her some options instead of just waiting for you.
Don’t you think it is selfish to just let her wait forever and then what if you decided not to marry her in the end. How would she feel? How would you feel if you were in her place? All that year(s) of waiting and nothing happened.
In my opinion at least give her some choices or a date, so that she wouldn’t feel like she “might” be waiting for nothing.
If you’re not ready to marry her at least let us and especially her know why. Are you not finically ready, mentally, physically? Let us know so maybe we can give you our inputs.