Do you think this sound right that I pay my babysitter 100 dollar extra because baby giving her hard time?

Of course your 3 month old is going to be fussy. Did you not expect that when you gave her the job? So you are paying her 1000 dollars a week? Daycares charge about 650 a month so she's dang lucky.You are better off sending him to a daycare for cheaper where people actually know what they are doing! Babies are going to be collicky and fussy...she's 19. I would fire her and get someone with experience who can handle a 3 month old and figure out what's wrong and what to do when he's fussing rather than quit. "The 3 month old is too fussy" makes me chuckle. What baby isn't fussy at sometime? I would seriously find someone with experience, she's not cut out for the job it seems like to me.