that she meant you were going to make more money like per hour or yearly, but that because your husband and son would be getting paid just twice a month instead of every 2 weeks, the paychecks will be larger every paycheck because they will be getting paid 24 times a year instead of 26 times. So those 2 “extra” checks would be added into other checks. I am sure you have already figured it, but for some who might have gotten confused; for example if a salary was 50,000 a year and a person got paid biweekly then the check would 1923.00 every 2 weeks, but if they got paid just twice a month then the check would be 2083.00 a pay period (before taxes, insurance, etc). I think that is what she meant by they would be making more.
I think things like this is why Dave mentions in his new FPU class that just because you live on a zero based budget does not mean you should have zero in your checking after everything is paid. That you need to have a cushion in there.