Zechariah questions Gabriel and is struck dumb. Mary questions Gabriel and is given an explanation.
I wondered why the different responses by the angel, so I Googled their two names.
The answer I liked best concluded with this: “Mary is not questioning if Gabriel’s proclamation will happen, she wants to know how it will happen. Whereas, Zechariah as a priest is not asking how it will happen, but rather he wants to know will it happen when he asks for further evidence.”
Happy Feast of the Immaculate Conception!