When you said they were on your regular or home computer, are they mixed in with family/friends photos or are they in old emails? Was OM a friend of the family?
Jack is right, it's so important in "how" you approach her about the pictures. If you decide that you have to say something....then make it about your feelings in this particular instance, and let her know that you aren't accusing or anything, but that you need her to do it to help you feel assured.
Think it over carefully, and for goodness sake.....be calm if you say anything.
((hugs))
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!