I hope you find what your looking for..
Now is she interested in swinging? It had been said before ( ask her ).. It sounds to me, that the two of you have an open line of communication, be open and honest with her, and with
your self Is this some thing you want to pursue as well?? If you good with it, then talking is the only way to find out if she is wants to get back into the swing of things.
If this was myself.. I would take her out for dinner and then find a nice quiet place to just talk. Be open, ask her what she would like to experience/do in the lifestyle, and tell her what you want to do/experience, ask her what her fantasies are, and then tell her yours.
Best of luck