Test of Pulling?

Alright, I have a mare that I got from sale barn (It was a "See it, like it, buy kinda thing...), and the former owner's friend said that she could pull. Well, I've gotten so many rip offs from sale barns, that I no longer trust anyone there. (I couldn't leaver her, she was one step away from being shipped down to Mexico.) Is there a way I can see if she can really pull without hooking her up to my nice cart?

Yes, I know it's a stupid question.

Not a stupid question at all! :)

If I didn't personally see (or have a friend who has, ect) a horse driving, I wouldn't trust that it does drive. Too dangerous! :) I would start off from the beginning: ground drive first (ok maybe that's more than the beginning, but...) and see how she reacts. If all ok there, work up to the cart just like you would be training a horse who's never driven. The only difference is you may be able to progress quicker since she's supposedly been driven. Much safer than just hooking up and hoping ;)

Yes definitely do not put her in a vehicle.

As suggested begin like your starting her in harness.
Take it step by step ... don't rush cos even if she is a quite harness horse, you may do something different that may upset her.

Yes, I agree. You really have to start from the begining. I also like to put a long pvc pipe through the shaft loop on one side of the harness. You will know right away if she is used to having something rub up and down her side. The pipe also makes noise as the free end drags along the ground. If she freaks out she probably hasn't been driven. Wait to do that test until she is ground driving well.