I am traveling on United from Frankfurt to Chicago in Polaris Business and I am Star Gold. I have a friend who is traveling with his wife and young child on the same flight but they don’t have status and they are in Economy. We all have a crazy long layover in Friankfurt and I would like to have them join me in one of the Lufthansa Lounges. Is this possible?

I’m unfamiliar with Lufthansa thus my Noob question.

Thank you for any wisdom!