You are doing good with what you have started. Maybe wait a few days then ask her if she gave what you suggested any more thoughts and ask her what her feelings are about the whole thing. Don’t bring up who just what she could do.
Maybe ask if she want to watch some porn about wife sharing
We were similar. Best thing you can do is get her to dress to show off and take her out, asking her to flirt and dance with guys as you watch from a distance. She can use the cover story she is at the bar waiting for a friend from work