DO NOT buy illuminate, it won't stop her from flanking you, instead, buy haven. Makes it so that it takes more than one one magazine to kill you adding reload time where she is vulnerable. Burst her down so she can't hit as man shots.
Try to make him waste his ammo, catching him on an empty mag is like catching him with his pants down. Try to make him panic and use reversal leaving him vulnerable. Don't track him through his dash place your crosshairs at the destination.
Strafe around unpredictability. Makes you much harder to aim at. Create angles with team mates so he can't hide behind cover to stop all damage. Don't try to 1v1.