important work question

My coworker has a dilemma I don't know what to tell her so maybe other opinions may help.... okay say you're at a ew job and been there for about a month or two it's part time hours but then get offered another job it's the same type of work but in the new job you would be the position you asked for and you get paid more.... so what would you do?? Would you leave the job that you've only been at for 2 months where you're okay with the position you have job security and you have friends at that job or would you take the new job that's the position you would rather have and that's going to pay you more the hours are also full time