Lets look at this logically QS...

if you just collect every piece of INTEL you have up and march to her mother's house and drop it inher lap what on earth do you think is giong to result from that?

Right now from what you write I can't see her mother dealing very well with it all.. She's too timid just like her daughter.. when you drop reality and serious problems in her motehrs lap she just ended up bailing on you didn'dt she?

SHe bailed on you just like her daughter's doing...

I am not saying outright don't do it but I am thinknig it through ahead of time to assess the likelyhood that it will result in something you will be GLAD you DID...

This is NOT something you can take back... So you really need to walk through it to assess the most liekly outcome before doing it...

I just can't see that going the route you want it to...

a. Either the mother will turn a blind eye to it all and ask you to leave
b. The mother will out you to her daughter and your wife will rage on you again and your intel system is blown completley...

I dunno... I can't see this happening :

a. Mother sees tihe light, hops up and calls her D demanding she go to family tehrapy and act her age
b. Daughter ends all internet activity and agrees to end promiscuous activities