My cat sits and looks out the window and makes this clicking, squeaking noise...?

Nope, it's an entirely natural response. She is seeing birds, squirrels and whatever else is outside your window. If she was outside, she would likely be stalking, hunting, and pouncing on things.

No worries, my cat always do that when she sees birds flying and flies in the house ;)

I kinda like it when she does that lol ;P

its called cat chatter, they do it whenthey see birds of bugs that they want to catch, my cat does it all the time when he sees squirrels lol