Was she beastly to Petruchio? (5)
I believe the answer is:
shrew
If this is the answer, I'm afraid I cannot explain it.
Can you help me to learn more?
(Other definitions for shrew that I've seen before include "Nagging woman" , "Mouselike insectivore" , "Petruchio tamed one" , "Small mouselike animal" , "Woman to be tamed?" .)