I don't think it makes you a walkover, but paying for her insurance is no longer your responsibility: It's hers. If she needs the car for school runs, then she needs to make sure she can sort that herself.
You need to stop asking her things, and start telling her things. If she won't meet face to face then that's fine, people have lives to get on with, but then send her a letter telling her what needs to be sorted. For example, tell her you'll pay the insurance up to the end of April, and the loan as well up to the same point. This gives her time to sort things, but also gives a final cut off that she knows to stick to.
In a few years time you'll look back on this and agree with me, I promise. I kept my other half on the mortgage of my old place for way longer than was healthy, and it did no benefit to either of us.