There is no good reason to hate Bellatrix! Yup Bellatrix is the one character I biasedly pick.

Bella is awesome but she did try to kill Molly's kids and taunted her, so I can see why

Bellatrix killed people she was close to, how could that compare to mere envy?

Rosalie hates Bella because...what?
She's human and can have a kid and Rose can't?

Lameee.

Bellatrix tried to kill her daughter...

Killed Tonks, a woman Molly liked very much, almost killed Ginny in front of her, and then taunted her about Fred. Also, she pretty much needed to die.

Rosalie is furious with Bella because she got the choice to be a vampire and was for it, when Rosaline wouldn't have. And Bella had a child when they thought it was impossible. That's not too big since Rosaline is a somewhat significant part of Renesmee's life now. I am sure she respects Bella enough anyway in the end, so I don't think she hates her as much as Molly hated Bellatrix.

Bellatrix killed so many close to her, even her son, Fred. Bellatrix is just freakin' nuts, so I don't see how many would like her (in the Harry Potter world, I mean). That's just a bit bigger than someone who I see is jealous of a rare chance of someone to choose to be a vampire.

Molly has perfect reason to hate bellatrix! First of all, Bellatrix is on Voldemort's side, the side that killed many people close to Molly, and second, Bellatrix tried to kill her daughter!

And Rosalie is just a bitch. She hates bella because she's jealous.

Molly is just annoying and she appoints. She just hates Bellatrix because she's a death eater and she sets Molly's 'beautiful' house into fire (I would do the same thing if I had the chance). I think Bellatrix has more reason to hate Molly than vice versa. Okay, and Bellatrix tried to kill Ginny, but so what. I hate Molly too much to understand her...