It's difficult to really know what to suggest I'm sorry and you're right in that it could be related to her blood sugar (or her blood pressure if that's high?).

If you have any Epsom Salts, try having her soak her foot in a bath or bucket of warm water and the salts.

I would be worried if she's been lying down for a very long time (days)and not getting up and moving around. How much is she actually moving around all day and what is stopping her from walking more, is it pain or something else?