First of all, even though we love our children and would never intentionally hurt them, most of us have done similar things at one time or another.
Call your pediatrician and see what he/she suggests. If your pediatrician isn't available, take your daughter to urgent care. Even if there's nothing wrong with her, you'll have peace of mind.
Here's a few of my 'bad mother' stories:
* After our son was born, I was exhausted from my C-section. I was holding him while I was in the hospital bed and fell asleep. My husband was sleeping on a cot next to me. I woke up and realized that our son was about to slide through the opening on the bed rail. Husband woke up at the same time and was also jumping up to get him. Fortunately he didn't actually fall, but it scared the heck out of us. The nurse told us that it's actually not that uncommon for tired parents to drop their babies that way.
* When the same son was about 3, I was carrying him down the stairs. I somehow missed a step and fell down the last three steps, with him in my arms. I took the brunt of the fall, but his head still hit the wood floor.
* I turned my back for a moment and when I turned around, our 2 year old was standing on the arm of the couch. He tumbled off and his head hit the floor.
* When he was an infant, I put him in his bouncy seat on the floor of our family room and went to take a shower. I was careful to shut the baby gate so our dog couldn't get in the room. Came back from my shower and found our 60 pound boxer laying next to him. Apparently I locked the dog IN the room with him. Still thank our dog for not eating him that day!
Kids are resilient. I don't think it's necessary to take her back to the ER or demand an x-ray, if she's behaving normally.
For future reference, here's our pediatricians guidelines for head injuries:
"Head injuries are very common in the pediatric population. Some children need to be seen after an injury and others can be observed at home. Your child should be seen if:
The accident happened at a high speed such as a car accident,
The accident occurred with great force such as a fall from a significant height,
There was a loss of consciousness, that is, he was knocked out or he was confused for a period of time,
The child has a severe headache or won’t quit crying,
There is repeated vomiting (2 or more times),
The child has neck pain,
The child seems confused or disoriented,
His pupils are unequal,
He is not using his arms or legs normally,
He has trouble with his balance or seems unusually clumsy, or
A bump on his head is larger than one inch in diameter. If your child cried but quieted down with consolation, the injury can usually be observed at home. Please follow the instructions below for 24 hours:
Keep the child as quiet as possible - no vigorous activity.
Give clear liquids for 6 to 8 hours since children often will vomit one or two times. Then feed him lightly for the remainder of the day.
Your child can go to sleep, but you need to awaken him after 30 to 60 minutes of sleep to check on his awareness, his color, and the strength of his arms and legs. (Have him squeeze your hands, and push with his legs against your hand to be sure the strength is normal and equal). After this initial check, again check on him every couple hours to see that his breathing is normal and his color is normal. If you have any doubts about his condition, wake him again. If you cannot awaken your child or any of the other symptoms listed above develop, call us immediately".