I was hoping to go for two sources of light - there's the window with the curtain behind the girl, and another, somewhat brighter, light-source to the right of the lady, off the canvas (an open door? An open window on the sunny side of the house?). Harsher lights might be something to try, yes. And the shadows might be made lighter as well, I guess, for the contrast feels rather overblown and artificial to me right now. If anything then it just reminds me of cold winter light at the moment, which might be explainable by the weather we've been having for the last four months. I've just...never really done light like this before and I really don't want to stop until I get the effect I desire.
It is a really sweet picture
But remember that the sun is only directly shining from one direction on the sky. The light will not be equally strong from both the door and the window, especially as the window have curtains.
There is no real source of cold colors in this scene. Even direct sunlight will not cause blue highlights in black hair, for example. I would suggest you do something like this, to bring the color scheme together a bit more:
What i did was to simply layer a warmer color over your piece and erase shadows into it. Rule of thumb for natural daylight is warm light, cold shadows. Cold light like in your picture would work well to illustrate a winter or nighttime scene.
Over all, try working with a more limited palett. Your colors are all over the color wheel right now - you have strong blues, strong cold yellows and strong warm orange hues. Pick a dominant color (blue, orange, yellow, ect.) and work from that, making the others a bit less saturated, or perhaps a bit closer to it on the color wheel. For example, if you want to make the piece a bit warmer, you can easily bring the dark blues of the womans dress into the range of unsaturated purple, or even red, and it would still read as blue.