I could expose this to her family here, but I really don't want to leave her open to the disgrace and shame.

If exposure to her family will result in shame and disgrace, they should be first on your list of exposure targets.
Dutch, you want her to feel shame! You want her to feel disgrace! You don't want her to feel entitled - you don't want her to feel good about her behavior! If no one knows but her and OM, believe me, they won't be feeling shame and disgrace.

D-Day 2-10-2009
Fully Recovered and Better Than Ever!
Thank you Marriage Builders!