Well, back track a little- you said her heels are resting on the floor alot of the time? I would say pressure/friction maybe? It sounds like she has alot working against her, perhaps flow issues in her legs, venous stasis? Lymphedema? I would find a way to keep the legs elevated to reduce the weeping, assess for compression wraps dependant on the wounds- they won't heal at all while they are weeping, and floating the heels to prevent further issues with pressure. The skin prep is great on the heels to prevent issues when sliding around in bed, but you still have to watch for pressure. Pillows, boots, (although I too work in LTC, I know sometimes the cost for the boots is often prohibitive in our world!) Do you have Broda chairs or Loungers that you can get the legs up? As far as the blister opening, my goal would be to hope it reabsorbs, then have the cap fall off later. But watch for infection!!! Especially if diabetic.