The old, old, old black and white film advice has come back!!! "Expose for the highlights, and develop for the shadows." Like Kathy mentioned in post #3, you need to use the "blinkies" and/or the histogram to arrive at an exposure where the highlights are not showin' up on review as flashing or blinking warnings of nuclear over-exposure levels!!! lol... Then, in post, use digital "fill light" to bring the shadows "up"...or use the curves tool to lift the shadows "up".
As KmH mentioned, spot metering might help; One things that often (not always, it depends) happens in window-lighting situations is that the window-lit side is pretty bright, and the shadowed side of a subject is very,very dark. The closer the subject is to the window, the FASTER, and more-rapidly the light drops off in intensity across the width of the picture! Soooo...it's easy to have a very large degree of light fall-off from even one side of a human body to the opposite side, or from the highlight side of the face to the shadow side. If you move more into the center of the room, and FARTHER away from the window, the light's fall-of rate becomes much lower, and the light is shall we say, "more-even".
Anyway, taking the above into consideration, what happens often is the camera's light meter can 'see' all that darkness, the shadows, and can cause you to OVER-expose the smaller highlight zones. And that is where spot metering right below the eye socket on the bright side of the face can be a valid method. That will ensure that you get a highlight-only reading, and then "peg" that as the exposure. Then, after the shot is done and at the computer, lift the shadows.