To be a Passenger or a Leader?

Played with dear sweet Aspen today and added a few new elements to the games.  Incorporated two barrels for the squeeze game and a carrot stick to our riding.  She wasn't too sure she could fit between the barrels as they got narrower, gave me some good 'question ears' at one point when I narrowed the gap, and then decided it was simply not enough room for her and came over to stand with me instead!  Though not really staying on pattern, it was sweet and I can't bear to ruin all this draw she's offering me at this point in our relationship! 

She was somewhat jumpy today on the ground.  It was windy and I think she was hearing or seeing something that I wasn't.  She only seems to jump when things startle her from Z5.  She was a little more tense off and on throughout our play session because of this.

Aspen got right into position next to the fence when I climbed up there, but gave me another grumpy look when I sat on her... eventually she relaxed at the standstill and I asked her to walk forward and she was fine and seemingly content.  I am wondering if because she's kind of bony it isn't very comfortable for me to be sitting on her bareback.  We haven't done more than a walk and I'm careful to maintain a pushing passenger position with my back rounded and not push my seat bones into her.... but maybe I'll try the saddle tomorrow and see if that changes her expression any.  I think I need more shims for that thing, but I'll see how it feels all cinched down (found a girth extender!). 

On the ground she's very content to be with me, not concerned about the other horses, and generally really relaxed.  I've noticed when I get on her that she has a hard time standing still, wants to keep walking and walking around and migrate toward the end of the arena that the pasture horses come over to visit.  She also becomes more alert and tense to surrounding stimuli.  I'm not sure at this point if I should keep doing the pushing passenger lesson, reinforcing the friendly game, relaxation, her ideas are good ideas, no pressure attitude, etc.  Or if I should be more assertive and get a stronger focus and give her some tasks or patterns to perform to help her mind concentrate and then let go of her tension because she has to think about what I'm asking her to do.  I saw Linda on a horse in one of her demos that had some issues being herd bound (his buddy was brought over to stand next to the arena gate).  Linda let him walk around the gate end of the arena for a long time before he eventually forgot about feeling the need to be right next to his pal and could more confidently move into other parts of the arena.  However, she wasn't doing a passenger lesson, she was giving him some direction.  Because Aspen's confidence goes down when I'm on her at this point I feel that some leadership from me is what she needs but I really want to make sure I go about it in a way that doesn't make her feel wrong or bossed around, and that helps her come to respect and appreciate my presence on her back.

After I was done playing with Aspen the owner of the barn and I got halters on her weanlings and turned them out to pasture.  It got a little intense but eventually we got the halters on, babies happy, and leading out to the field.  I've included some pictures of her daughter with the weanlings and helping me brush Aspen today.