Just to clarify, did you mean that she says no to you attending appointments or being given medical info? If so, that does make things harder. While HCPs can't give out personal information without consent, there is nothing stopping you writing to them and sharing your views and information about what she is like at home. They might be able to influence her, but it is a long shot.
If she doesn't want to test at home, there is probably no point in trying to get her to do it, when it's clear the result will be high. Better to focus on getting her to have medical appointments and get tested there.
There is, however, a serious medical condition you need to be aware of, if you're not already, that a T2 can develop with very high sugar levels. I don't want to add to your worries but knowing about the condition may help if she starts to show signs of it. Maybe you can negotiate that if she appears to be developing this condition, she will do a BG test to help her/you decide about her going to hospital for treatment. It's not ideal of course, but if she becomes semi conscious, then calling an ambulance and shuffling her onto a stretcher is one way to get her to hospital. This condition can occur when her BG levels are above 33 for some time (and the home BG meters only go up to 33, higher than that and they say "HI". Here is the info:
http://www.diabetes.co.uk/diabetes-complications/hyperosmolar-hyperglycemic-nonketotic-syndrome.html