Sindy, I wouldn't suggest that you talk to her daughter, but I would suggest that you talk to her priest right away. Ask for his help in ending the affair. The more exposed the affair, the less able it is to survive. Exposure brings great conflict into the affair and makes it very uncomfortable.
In addition to exposure, you also want to confront, without lovebusters, at
every opportunity. Plan A is NOT about making the WS comfortable, but about making it UNCOMFORTABLE for them to carry on the affair. You should be doing everything in your power to END the affair in Plan A.
Here a couple of good threads about Plan A:
http://www.marriagebuilders.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=37;t=020829#000000Here is a post from MB coach, Penny Tupy, about Plan A:
Plan A is not (repeat NOT) about making the WS happy, or feeling good.
Plan A is NOT, contrary to popular (and very incorrect opinion), about "making yourself a better person," or "working on yourself."
Plan A is ALL ABOUT the straying spouse. In Willard Harely's ever brilliant words, Plan A is a stategy to end the affair and to entice the straying spouse to reconsider the marriage.
So, it has several elements that should be done at the same time.
First is to eliminate LBers and to meet needs as best you can... recognizing that the unfaithful mate may not allow the betrayed partner to meet needs.
Second is to CONFRONT the unfaithful partner with what you know. Doing so (of course) in a way that is respectful and about you... how you feel, how you are affected by the affair.
Third is to expose the affair to the scrutiny of the world. The lover's spouse or s/o, coworkers, family, friends, church family, children, etc.
ALL OF THAT is Plan A. And it should be done as much as possible simultaneously. (If you don't believe me call the radio show Mondays and Thursdays at 1pm Central Time and ask Dr. Harley for yourself.)
Plan A must have a deadline. It's called Plan "A" because there is a second step... aptly named Plan "B." Willard Harley suggests a max of 6 months for men and 3 months for women before going to the next step. If Plan A hasn't worked in that time, it's not going to.
(I challenge you to find anyone who has done Plan A longer than that and been successful. I define successful as the A ending, n/c promised and verified, and the couple working a good recovery plan which includes meeting needs, eliminating LBers, getting in 15 hours a week of UAT, and most importantly following POJA.)