Do you consider this abuse?

A three year old throws a fit kicking and scream so the mom spanish her, the child cries more so she smacks her in face kid cries harder and pinches the mom so the mom pinches her about as hard as she can till the kid sits in her seat and sobs. Another senario, the child asks later that day if she can have a drink after spilling a drink and shredded paper the day before and the mom tells her no all she will do Is spill it and starts cursing at her and telling her to sit her a** down and don't spill it. This is my baby sister would you say it's abuse it's my stepmom doing this she always smacks her other boy in the face if he does something wrong and makes her other boy do everything she wants. Thanks