try not to beat yourself up, it happens to pretty well everyone and she is most likely fine. I would just keep an eye on her, let her sleep but gently stir her every 15-30 mins. You dont need to wake her just enough to get a reaction.

Signs of concussion can include- vomiting, lethargy, uncharacteristically unsettled, bruising behind the ears/ around the eyes, confusion- ie not recognising you/ familiar surroundings

Go with your gut. If you feel something is not right get her checked out. Even if she is fine it's better to have that piece of mind if you're not sure.