The suspect made off with the woman's cell phone, pocketbook and an undetermined amount of cash and fled the scene on a black BMX-style bicycle.
The woman was taken to Kings County Hospital where she was treated for lacerations and bruising to her head and face. The 4-year-old was uninjured.
The suspect (pictured above) is described as a Hispanic male between the ages of 15 and 20. He is approximately 5-foot-4 to 5-foot-7 with black hair and a thin build.
Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS.