Mt sister's shih tzu fell about two feet off the ground. Is she okay?

She was limping for about two minutes after she fell. We were worried she had fractured a bone. She landed laying down and she hit her head. We heard the fall. After about two minutes, though, she began to run around and hop as if nothing had happened. I had her in my arms and had knelt down to let her run around the floor, but she slipped off my arms before I could put her down. We checked her feet, paws, and head for signs of injuries but everything seems to be fine. She's not whinnying and doesn't cry when we examine her. She is about to turn four months. She's still running all over the place and doesn't seem to be hurting. I'm just worried since she was not limping, but kind of hopping for two minutes after she fell. Thanks.