The room looks like it has more than 4 sides (the entryway). As long as you have at least 8-9ft on the short wall (opposite the desk), I would go with the 8x10. I wouldn’t want the corner of the rug to “stick out” and become a tripping hazard.

With a doorway not squared, I'd be tempted to try a round rug and I'd want it to cover the vast majority of the floor to give your daughter a soft surface to plop herself down to play.

It sounds like the 8x10 would work, but mark it out on the floor with painters tape to see what you think. Get a low pile rug so it's better for playing on.

Pretty space!! Love the desk!!!! I will also recommend taping it out and posting a picture/ deciding yourself if it works ☺️

Thank you everyone for your input and suggestions!

Map it out on the floor, either with tape or use objects to mark spots. If you can go with the bigger size, I’ve never regretted it.

Great rug! I would also suggest getting a thick rug pad underneath. I know my son prefers to play on the ground when it's softer.