Resource guarding should be adressed immediatly. Taking the object from her is only a temporary fix. The behavior is conerning in itself. “Claiming” your space and everything in it is important. Don’t get me wrong, I’m not advocating strong handed methods. Simple assertivness is the best way to do this in my opinion. A calm but firm approach, with positive reinforcement at the core of the training is always best. I would humbly suggest you study the issue of “Resource Guarding” and seek a long term solution. Pitbulls are smart and eager to learn. Good Luck. Hope you can get to the root of the problem.