I can't make my Mom understand.

My mother is in her late 70s. Last year I turned her in to the Secretary of State/DMV, expressing my concerns. She was called in to take a test, failed it twice, and lost her license. We've gone through ups and downs getting a state ID. One time she brought the wrong information and we had to sort some matters out (her Green Card had her maiden name, not her current name on it, so that complicated things.) So I get her in to get a state ID,all goes well, and it's coming in the mail within a week. Yesterday she calls. She is all excited because they gave her her license back. They didn't. It was a state ID, and that's how it's labeled. They sent her a form letter saying here is your license OR your state ID, and now she's making plans to get her license and plates. I've tried to explain to her, and so has my husband, that this doesn't permit her to drive. It is only an ID to use at the bank, etc. She does not get it. We asked her, what did she think was happening when we took her to the secretary of state. No clear answer, but she blathers on about how they took her picture, etc. I told her, fine, then take a cab or get a ride (I'm not doing this again and again) and see what they tell her. She says if she doesn't get her license she's moving back to her native country where they have good public transportation. My response to that was, fine, do what you like. She makes threats all the time: whenever she's not happy it's a case of "I'm going to hang myself in the trees in my yard," or "I'm moving out of the country" and so on. When she was more able bodied, she would move when she was frustrated about a place, but now she can only talk. But how does one get it through to a stubborn parent on such matters. She will not believe us that it is a state ID. I mean, I was there when she applied for it. I know what it was! I know I didn't imagine it. I'm not sure what she knows, though.