I, like you, would tend to mobilize the GH joint too. If not to improve mobility, to assist with some kind of neuromuscular / proprioceptive input (i.e. mobs through range...). I feel it works well when there is impingement.

Do you know what the U/S report really means when it says, "soft calcification" with "no disruption to the r.c. tendons"? Because i'm not sure i really do.
Does it mean that the calcification is lower down on the greater tuberosity and therefore not affecting any area of the capsule? Could it then be affecting the deltoid? I can't imagine there being calcification in the shoulder girdle and it NOT affecting some of the musculature in the area.

However... because her pain seems to be quite mild (and perhaps unlike the pain usually associated with calcification) and comes on late in abduction, I would still look at her pattern of movement. Does she actually impinge? (Hawkin's test / Neer's test?) Does she hike her shoulder at 100 degrees of abd'n? Does the tone in her upper / middle / lower traps change as she goes through range and what happens at 100degrees? Any palpable tight bands in the deltoid or upper traps?

??........