I don't think there was a struggle. For all that Aunt TB says she taught the girls how to resist, there's no way to know if an individual will fight back until the time comes.
If there had been a struggle, I would expect to see blood, maybe hair, maybe bits of ripped fabric. The reason I'd expect to see blood is because the trail is paved. Being knocked off her feet would probably make either girl bleed since they were both apparently wearing short sleeved shirts and shorts.
Especially if a loved one is there and involved... I agree with you there should be SOMETHING but maybe it hasn't been released.I hope.