No, she hasn't hit any curbs. She'd be pissed if she messed up those wheels. Vibration seems to start around 65mph. Haven't felt any low speed vibration. No vibration when braking.
A loose ball joint would cause high speed vibration?!
Loose ball joints, outer tie rods, inner tie rods, wheel bearings, and yes axles too. Some axles have a balancing ring if it comes, off it could cause a vibration.