Right now, while it sounds cool, her powers don't offer anything that an ordinary person with a little boxing training couldn't do. Why not? Because you've neglected something known as:
Required secondary powers
She gets hit by a truck, she's a stain on the ground. You've given her the ability to react like a rubber ball to impact, but even a rubber ball has a breaking strain and in practice it's not all that high. You haven't given her a breaking strain any higher than an ordinary human. Punch her with a force sufficient to break her wrist and if she tries to return that force she'll break her own wrist.
Practical physical limits
She has a power, but it only becomes a superpower when the required secondary powers are allowed for. Define them, start with strength, healing, resilience, then limit them. Those are her limitations, she can stop a car, but not a truck, if she takes a beating she's down for a few days, etc. These become her practical physical limits.
The real benefit of her power now lies in combat efficiency, she's expending the power of the impacts she's received rather than burning her own energy, but to do that she has to take a bit of a beating. Her combat complexity lies in knowing when to take a hit to get that boost rather than dodging or blocking everything.
In terms of superpowers, as long as you keep the secondary powers under control you shouldn't have a balance problem here.
With the above allowed for, gear is stylistic and tells you what sort of hero you're after. Captain America has a shield and punches people, lethal force is not his schtick. Deadpool has guns and swords and all the toys, lethal force is very much his thing. Gear becomes about how your hero presents to the world, to kill or not to kill. Weapons or fists.