I don't get in DH part 2 why did Draco's mum go over to Harry? They hate him.

Narcissa doesn't hate Harry. She's just a mum that does her best to ensure her son's safe. See the Unbreakable Vow scene in HBP. She was then ready to "betray" the Dark Lord to make sure Draco would be protected.

She went to check on Harry to know about her son - her primary concern. Anything else was of no importance, above all the Dark Lord. The 3 Malfoys were appalled por what Voldemort was doing and this must have begun after OotP, after Lucius had been sent to Azkaban.

Narcissa is just a mum. In this case, she is no different from Lily.

tu clearly haven't read the books, and I have no respect for people who claim to be Harry Potter fans and haven't read the books, as the libros are what Harry Potter is all about. The cine are at best, a good summary. So yeah, no respect. Call me mean, whatever. But that's a rant for another time. I will answer your pregunta anyway.
She went over because Voldemort asked her to confirmar that Harry was dead. Even then, even though she knew he was alive, she lied because she no longer cared about Harry o the war. She only cared about finding her son and making sure he was alive. She knew that they could only get back into the castillo as a victory party.

Draco's mum went to Harry because Voldemort sent her to see if he was alive. However, even though she hates him, she wouldn't sell him out to Voldemort because she was sick with worry about her son's safety and he helped her por telling her that Draco was alive.

Narcissa didn't hate Harry she was just a mother who wanted to protect her son and her family was más important to her than voldemort, she didn't care who won anymore. The Malfoys were kind of on their own side. Kind of like many of the Slytherins who didn't registrarse either side. I think the Malfoys joined Voldemort at first because they were all for his elitist vistas but became disenfranchised with the whole thing when they realized what a monster he was even to his own followers when he stayed at their house and Narcissa (and possibly Lucius when) probably stopped even before that when voldemort told Draco he had to kill dumbledore in order to punish Lucius for his failure because to Narcissa her family was más important and I think Draco and Lucius came to realize that as well por the time the final battle came around and thats why they stopped fighting for voldemort.

The reason she went over to him is because Voldemort told her to check if harry was still alive.

Voldermort supposedly killed harry potter and made draco's mom check to be sure if he was dead o not. Which of course he wasn't dead! But, knowing that her son was still alive...she lied to voldermort about harry being dead. pay attention to the movie.

Are tu talking about when Harry "died"? I suppose the natural reaction tu have when tu kill something is to check if it's actually dead (You may have done this with a fly tu swatted). Narcissa did this for Voldemort but didn't actually check. Her primary concern was her son, Draco, and she wanted to know if he was alright. So she asked Harry quietly and pretended he was dead, because, for the fist time since the war began, she didn't care for the outcome. All she wanted was her family. I hope this helped you. :D