My bff being abused?

My best friend Is being abused by her parents . (No im not saying this for myself , my bffs parents really are abusing her) . Her mom hits her in the back with a broom , she slaps her across the face , and other things. Im worried about her because shes my best friend and i hate to see her get hurt. should i do anything? i told her is her mom does this again , call the social workers and tell them but she hasnt. please help.