I did my neighbor a favor after the snowstorm and she made me feel foolish

DEAR MISS MANNERS: Following a snowstorm, I went to clean off my car in its space in a reserved lot. An older woman who parks in the adjacent space was doing the same. As I was shoveling out my space, she was knocking snow off her car and letting it pile on the ground.

I understand that older people face physical challenges, as I am in my mid-70s and heavy lifting is increasingly hard on my back. As a favor to her, I not only shoveled my space, but also cleared the piled snow from hers.
After that, she did another round of wiping snow off her car, knocking it into the area I had just cleared for her. So I reshoveled that snow.

She finished sooner than I did, and departed without either acknowledging my help or thanking me for it. I felt a bit of a fool for doing a favor for someone who didn’t care.

What do I do the next time it snows? Will I deserve the glare I’ll get if I fail to clear her space? I don’t wish to create an adversary, but neither do I wish to be made a fool again.

Either way, I won’t expect a “thank you” in the future.