Its just a phase.
My kids do that too.
Normal.
Don't worry.
It is important, for a "daughter" to feel bonded with their Dad. Or their Mom.. and a child will seem to prefer one or the other at times. Normal.
It is also her age.
A good book is: "Your 3 Year Old" from Amazon.
or, do a Google search and research "3 year old development."
At this age, their emotions are still not yet fully developed, and their sense of self. So many things, they are experiencing.
All normal.
I remember being that way with my Dad. I just ADORED him. And he was such a good nice Dad.... my Hero.
all the best,
Susan