My 9 month old hit her head 😕

So my 9 month old was laying on our bed with me, in between my legs, so I could guard her from falling off. She ended up flipping over my leg onto the floor and hit her head, it happened so fast and I tried to catch her but I couldn't. I picked her up and consoled her, I was shaking and on the verge of crying with her. But she ended up getting really sleepy right after, and she ended up falling asleep on my chest, so I can know if she's still breathing. She wakes up at 9 and its now 1:30 and she's due for a nap, but should I be worried that she got incredibly sleepy right after it happened? I'm so worried I'm shaking and I don't know what to do, if anyone could tell me if I should be worried or not. For context, we just gave mattresses on the floor, we don't have a bed frame so she fell from maybe a foot or a foot and a half