[Ri2]

be upfront with her about this and admit to her if there is anything that you consider that you could have done better in the past situation. admitting your faults can indicate awareness and growth. you have to at least give her a chance to choose and do what she feels is right. by letting go of it right away, you're robbing her of that choice and yourself of the opportunity.

if your new chick likes you as much as you like her, then she will stay.
granted that you're older, she will have a clear idea of what she is getting herself into and will realize her choice to stay is her risk and hers alone.

people make mistakes, we're not all saints. if we were all to swear off dating people who fucked with other people in the past (on or not on purpose), there'd be no one left to date, lol.

good luck!