When I'm struggling with the 'realism' of a design, I oftentimes find myself referencing photography.
What you are looking for is ambient light: the light which is already in the room before any objects are added. (which is also kinda what user287001 is hinting at)
In your case, the ambient light is warm yellow sunlight, coming in through the orange curtain, and reflecting off the brown hut walls. Now imagine you had a perfectly white piece of paper, and you could place it where the girl was sitting. What colour would it appear to have? Certainly not white!
Look at the picture below for example. Look at the woman's skin. It has a greenish tint, doesn't it? But you and I both know people aren't greenish! Her white blouse is greenish too. The green comes from the surroundings, from the window, from the books and shelves, maybe from the ceiling or the floor.
The problem is that we are so used to this, that we don't notice. Our brains deceive us and compensate: they tell us her blouse is white, while it is obviously not. They tell us this is obviously not a sickly person, so her skin is not green.
So how can you adapt this for your illustration? Add a brown overlay to the present and the girl, and set it to Screen or Color, and you'll see they suddenly become part of the picture instead of popping out of it.
Photo by Donny Jiang on Unsplash. This picture is an extreme example to illustrate the point, and actually suffers from poor white balance.