Can trauma to the forehead cause black eyes?

My mom just came by from mexico with my dad. She had two blacks eyes and a large lump on her forehead. They were gone for two weeks and she said it happened on the first night of the trip. Her reasoning for the black eyes were that she had been sleep walking, fell down, and woke up to my dad icing her head. She has no history of sleepwalking. She fell down in an apparently open area onto a tile flour. She weighs about 140 pounds, and is about five feet four inches tall. I ask her if she had the symptoms of a basilar skull fracture and she did not have any. I just don't believe it is possible for an injury of that magnitude to be cause by simply falling or ping out. Both of my parents are alcoholics. I really want to know if my dad hit her. My mom has also admitted that her ex husband was abusive. I like to think of my dad as a good man, but her story doesn't seem to add up. I plan to call a doctor tomorrow to see if it's possible for head trauma to cause two black eyes. My opinion will be most effected by the answers of the doctor. It is also possible that she is on blood thinners. I read that blood thinners could possibly cause excess bruising. Any advice would be appreciated.