Is this abuse,read additional detail?tankyaaaaaa.?

Right well basically im 14 and i have a friend tha same age and she has problems at home with her perants.and she does not no what to do because sometimes her perants can e loverly and really nice and kind,asif they would do anything for there child but other times they can be really nasty perants. and its not liek she desreves it like for example the other she spilled her drink on the floor and her mum went mad at her and hit her on the arm/shoulder area.and she went into her brothers room one morning to get a chocolatte bar for her break because she had nothing els,and her mum came in shoutung who the hell do you think you are?and grabbed her outa the room and hit her.at the end of the day i no kids at our age can be little shits and do deserve a slap but my friend really doesnt.maby occasionaly she is cheeky and desreven a little hit.but i mean spilling a drink?its an accident and accidents happen tbh.and her mum is always saying how the brother is the prefered one.....little things like that happen allot ?if you say this is abuse i will talk to her and tell some one ammediatly but just getting a second oppinion? should we tell a teacher or somthing?thanyouuuu,and jsut to say normally sheis a happy girl its just sometimes she isnt her self and we always know why :)and its like her mum dont ever starve her or anything like that she always gets the food and drink that she needs allowed her frinds round allot and allowed out not really stit or anything its just sometimes she getts inhappy?x