Although it's nice that you've provided all these pictures, I'm still left with having to assume the situation. It looks as though you have a 2 degree pitched roof with that shed dormer. And in that case, there apparently may not be an attic access door. So, short of going to a structural design technician, since you are in the remodeling phase and will be doing some sheet rock taping, I'd say poke a hole in the ceiling big enough to peak through and if you find that the ridge is not supported by the wall in question (with vertical supports) and or support studs are tied inot the ceiling joists from the ridge, then... IT SHOULD BE!!
I suspect that when the dormer roof was framed, they may not have supported the ridge onto the ceiling joist. If you see supports that are tied into the ceiling joist from the ridge, then it's load bearing.
So yes, based on your pictures and information, this wall WILL be load bearing if it was framed properly. If there are no supports to that ridge, I am 99% positive that the ridge will sag over time if your in an area that gets the winter snows. If you never get any snow, then the only weight is that of the roofing materials and framing. In which case, if you don't see any sag at this point and the structure is older then 10 -15 years, then if there was going to be any sagging, it would of happened by now. But in any event, if and when you open up the ceiling to take a peak and find no support, I would add a couple anyway (2- located every third mark based on the width of the dormer roof) and don't worry about the opening for the wall. I sure wish I could be there to see, all this could answered in meer moments of looking at it.
Hope I didn't throw to much at you. Looking at the drawing below, you should have support just below the ridge where you see the red lines. This indicates where bracing should be to help support that ridge over the spam that represents the width of the dormer. There are seperate red drawings there; each one shows an option. Either straight down from under the ridge to the ceiling joist or to right and at a slight angle coming down on the joist.