How do I keep Jane from triggering the trap in the secret lab?

I think that I am susposed to insert the key into the key hole after the magic key has been made am I correct? Ok. Every time I insert the key into the key hole
Jane appears and then scolds Nancy. Afterwards, She asks "WHAT IS THAT" then goes over and picks the object up. Once this happens both Nancy and Jane are trapped. Help how can I stop this from happening?

Just step back quickly.

julesy