If you can be her friend without wanting more and be mature about it, I suppose there is nothing wrong with this.
But, can you really do this? Package your romantic feelings for her away in some corner of your mind and never look at them again?
If you are serious about this, then what you should do is find another woman to love and focus your romantic feelings on. If you do this, maybe then you can truly just be this woman's friend. But right now this is just a recipe for an affair at worst and you getting yourself shredded at best. I'm sorry.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh