Turtle fell, shell hit her head...?

i had just made a new turtle topper basking area, that i may have needed to make a few adjustments for... and my turtle escaped, falling approx. 4 feet to the floor. i have 2 good cats so they didn't eat her, i checked her, she seemed fine. but the next day i noticed she was low in the tank, sleeping, or napping... this is odd she never sleeps mid day. but when i approach her she seems to wake up and acts normal. i looked at her again--- ** and on her head between her eyes, actually nearly missing her left eye is a small indent.her shell hit her head on the fall, and it left an indent*** im devastated shes 4 yrs and is about 8 inches long and pretty heavy, her skull is not cracked, but her behavior is not right. active and then "napping" could she be healing, it doesn't look bad exept for the visible indent. if it continues tomorrow ill look into a herp, but i was just worried, maybe shes just dazed or her head hurts? idk... i just feel awful...