Hopefully in time she and all people will see you making different, mature choices again and again and will gradually form an improved assessment.
It's really frustrating to be patient when you know the truth and you wish people would get with the program--but a bad history takes awhile to erase. People are tentative: they need to "trust, but verify" for awhile.
It may not be fair, but it's understandable when people are used to being burnt.