A bitch with purpose is someone who bitches about someone in the hopes that they hear about it and change their ways.
Jessica : OMG!! Look at what she's wearing. Nah hun (Gina) that aint right for school.
*Rumours spread around school that Jessica said this about Gina
Gina: oh i guess she was saying it for my best interest because Sasha got told off for wearing the same thing as me yesterday. Thank god Jessica is a bitch with purpose.
The queen bee of a crew the one that calls the shots whether the others are fine with it or not. The one that in a sense brought the crew together but not necessarily the one keeping it together. An example is Regina George in Mean Girls
Polly: Remy is such a bitch central ain't she.
Nelly: hell yh you can just see the way she runs the show idek if the crew likes her but she be calling the shots tho.