How to deal with 'friend's' moral issues?

You may want to change tactics. Rather than confronting Clare you may want to accept she is who she is. Sometimes we can't be friends with everyone and if Clare is a person who you can't relate to, limit your contact and/or conversations with her. BTW, even though Jess smokes in private, the residual hydocarbons (third-hand smoke) are as bad as second-hand smoke.