How do you feel, ditching your girlfriend for an FWB? Would you have stayed with your girlfriend otherwise? Then again, you managed to move on from her very quickly even though you had no interest in your friend until she said something.
Don't bother waiting for this friend to change her feelings, because it's likely you'll find someone else in the meantime
and move on again, until you develop your emotional maturity enough to understand what you are looking for in a partner.