Have you tried having guest speakers, challenges, one of your members running an "in-house" course or having a professional coming in and run a course. That obviously depends on finances of the members and the guilt.
I am not sure what time of the day you meet - my guilt meets on the second Sat afternoon of each month and we have an afternoon tea roster with two ladies providing afternoon tea each month. Have your "show and tell" followed by afternoon tea then the meeting - that way you have the fun part first and then the business part. That will keep all members present longer.