I know of 3 cases of internet infidelity by women that broke up marriages.

One other that just missed, hubby caught her and basically blackmailed her into staying.
I dunno if l would of gone that route but he did.

Thats just in the last few years.

Chatting on sites out of boredom seems to get that ball rolling.

Check your browser history? It will prolly give u some idea where she's been doing it if thats the case.

Phone records?

Hope it all tuns out...
Good luck