PigPen,

I think it is okay to reach out to W and let her know that the cousin had been in touch with you regarding the M. You would want to do the following:

-touch base with W and ask how she's doing
-ask her if she is willing to talk
-preface by saying that you stayed away out of respect for her
-you are taking a risk here
-feeling scared here and say that you can only imagine she probably scared too
-seek a confirmation that W did indeed say such words to cousin
-state firmly and calmly that you want her and the M
-it seems that two people are in a world of pain and not knowing how to reach out to one another
-hope to begin slowly build bridge somehow
-this will require patience and understanding from the pair of you
-then nicely end the call with an appreciation for her willingness to talk

Listen and validate.

Say you have had some time to do some reflection and introspection.

I think you are more than ready to handle this talk. What do you think?