One mom I had use to joke that it was the learning to walk perpetual bruise on the forehead! She even had a theory on the right or left handed by which side was bruised!
It happens. I would say something to mom like "you do realize the next month is all bumps and bruises until she gets her sea legs! This is why their soft spot doesn't completely close until after they are walking!" That said I would try to keep her on softer surfaces... carpet, grass etc. My dd sliced her lip open when she was learning to walk.. 3 stitches, she lived. But it is amazing how some kids really are the ones that bang "all the time"! and they tend to stay that way.... yup my dd had her lip glued together at college this past year!