Was it really necessary to put in the phrase - "..bought with my babysitting money" ? Does she mean her job as a babysitter or is it just an adjective ? How muc

Was it really necessary to put in the phrase - "..bought with my babysitting money" ? Does she mean her job as a babysitter or is it just an adjective ? How much did babysitting pay that you could afford a computer with that stuff ?