There is no reason to assume her technique will improve as she ages. There's maybe five people who understand the physics and individuality of sprint mechanics and fifty thousand who say they do.
I saw the downvotes of earlier posters saying she needs to lose weight, but the truth hurts. That extra mass is a hindrance to performance and she is going to suffer a serious injury in the next eighteen months without addressing the weight. She's putting so much force into the ground while running imperfectly enough that the end range of her stride to stride variance is already in the dead center of dangerous. If she adds another twenty kilos to her back or front squat and her mechanics don't improve, unfortunately, she will get hurt.
My bona fides: I can claim with some degree of confidence that no other sprint coach has taken more female athletes from under 18 mph to over 20 mph over the last three years. For male athletes, going from sub-21 to over 23, I know I'm somewhere in the top twenty. High school sprint coaches in America are fundamentally retarded and so much talent is wasted. Best example is trained a junior girl who went from alternate on a 4x200m that wasn't any good to trouncing the fastest girl on that relay (who had multiple D1 offers) in eight weeks. Flying ten m time of 1.22 to 1.063.