This may be the official tie-in comic to The Amazing Spider-Man movie:
The Lizard was tossing card around like they were toys, and it was all I could do to save them (thanks to the combo of my super-strength and artificial webbing)
Spider-man: Whoa! Whoa! Whoa! Hey! Not cool! You're just going to throw a car and run?
I wanted to go after him. But I heard screams for help.
Father: My boy Jack is still in the car!
So I did what I had to do.
Jack: Daddy, help!
The boy was terrified. I guess I broke superhero rule #1 by taking off my mask. But I had to do something to calm him down.
Spider-man: See, Jack? I'm just a normal guy. Here, put [my mask] on. It'll make you brave. [Jack puts on the mask] Okay, see? Now I want you to reach out to me as I climb in. Now! grab my arm!
[Spider-man zips out of the falling car, holding on to Jack]
Father: Oh, thank you...thank you. Who are you?
I felt strange but exhilarated -- I was starting to to realize that I really could make a difference.
Spider-man: I'm... Spider-man.
The child in danger is a boy, not a girl, and there doesn't appear to be imminent danger of discovery (as was mentioned in a comment on the question), but it otherwise seems to fit.