I hope you can get her to agree that since you've both been-there-done-that and can't fabricate any feelings of joy (as required) over this, you might ditch it next week... and the next...
This comment reminded me of my old roommate. VERY faithful sister. She was in her late 30's / early 40's at the time and desperately wanted to be married - but only 'in the lord' (or to a nearly active 'brother').
Third time thru the Family book, she just couldn't do it. She told her PO dad that she would sit this one out and return to the book study when they were done. She felt just a little guilt but - man!! - it was just torture for her. I was impressed that she stayed away.