The red carnation symbolized the beginning of the relationship...
Choose a different flower/color to symbolize your new beginning now...
She would probably see the red carnation as a last ditch attempt at you trying to prove once again how much she is losing/lost/can't live without etc...
May All Who Seek To Take My Life Be Put To Shame And Confusion; May All Who Desire My Ruin Be Turned Back In Disgrace. ~Psalm 40:14~