Power steering fluid in the transmission

To the OP, I'm assuming your car has an automatic. If so, 12 oz of PS fluid shouldn't be too big of a concern given the volume of ATF and the fact that "PS Fluid" is basically ATF without the friction modifiers which aren't needed in steering gears.

The correct fix would be to drop the trans pan, drain the converter (if possible), blow out the cooler lines, replace the filter, adjust the bands, and refill with fresh fluid. In other words service the transmission.

Personally I would just drive it, but put a transmission oil change somewhere near the top of your to-do list.

And, if you have a manual trans, simply drain and refill. Which is easy because it has a drain plug (you should consider adding a drain plug to your AT pan while it's off).