My most joyful and moving moment was when Claire (who isn't/wasn't into people at all) leaned her head against my shoulder while I was holding her when her hooves got trimmed.
Her usual behaviour when she got approached was to turn her head away. What I do is I stop about 1-2 yards away from her and wait. If she turns her head towards me I approach and if she turns the other way I either wait or leave depending on how strong the signal is. But nowadays most often she turns towards me. About a year after I started this pattern I read K.F. Hempfling's statement that mares most of all need our respect - this is certainly true for Claire.
Maria, your experience is so wonderful - I love your blog about living with your horses!!