I'll level with YOU. This kitten is out and far too young to be so. She may not be fixed, she may not be vaccinated. Cars are only one of many worries, especially in an area inhabited by coyotes and cougars.

This kitten is not out and about in an area free of predators, disease and traffic. It's out and about in a danger zone, despite your intervention.

In my heart and mind, there is no doubt that you taking her would be anything short of heroic.