If a student tells a teacher "venga" when she wants the teacher to help her, is she being rude?

Like I know it means "come," but she's not saying por favor or anything. It's just venga and a hand motion. It's striking me as rude, and I just want to be sure before I tell her to knock it off. I am telling her to say please, though lol and she's not. Le sigh.

Thanks in advance.