Hey My Niece Sprained Her Knee(?) And They Went To

Hey my niece sprained her knee(?) and they went to the hospital and they prescribed her ibuprofen 400mg and norco 0.5s, which is odd because she's only 10yrs old, but I'm assuming it was just that painful? So she got home and from the knee down it swoll up twice its size, bruised very badly and became VERY cold to the touch. Wondering if maybe something else could be wrong or if this is normal? Thanks for your time!