Hate having to do this, but I need help getting my grandma metformin as she has run out and healthcare cut her off.

My 68 year old grandma is Type 2 Diabetic and takes 2000mg Metformin a day. I had some old meds I gave her that I don’t use anymore because I use insulin. But her healthcare insurance cut her off and is refusing to refill her prescriptions. She ran out of metformin 2 days ago and her sugar spiked pretty high today and doesn’t wanna go down. I can pay any costs/shipping if need be because she needs her meds and she’s scared of using my insulin (besides I don’t think that’s safe anyways). Any help would be appreciated! Thanks for taking the time to read this!