Dramatic Female Monologues?

My acting coach says that I have a wide talent range, but wants me to push myself. He says I need a dramatic monologue from a generally strong female character who is experiencing a rare moment of vulnerability (she may be looked at as sexy as well). He would prefer it to be from a more obscure movie if I can find one. I have been looking for weeks, and can't find any. I have also watched about 20 movies in 2 weeks while looking, so my time is getting very limited. So if you could offer the actual text of the monologue as well as where you found it, it would be largely appreciated. Thank you so much! :)