I''d like to chip in my 2 cents worth, if no one minds.

A) Listen to Irish..he's very correct with what he says.

B) Find out if there are things away from the bedroom that are causing her distress. Many times issues from work, or other places can cause depression or stress that makes one become Very inhibited and withdrawn. If these other things are creeping into the bedroom, try and find a way for her to keep them out, and your sex life could/should improve.