Sometimes parents get a little frustrated when kids ask a lot of questions, but you keep asking them. Smart kids ask a lot of questions.
Money, and managing money, is a big part of why marriages fall apart. Adults fight about money more than anything else. Student loans are a big expense, and must be paid. If your stepfather is managing the household budget, you have to count on having so much money coming in to pay the bills correctly. When you have a house and a family, there are lots of things that come up unexpectedly that you have to have money for—the water heater stops working, the car breaks down and the bill is quite high, all of these things cost a lot of money, and if the money you have is just enough to cover your regular expenses – mortgage/rent, lights/heat/, cell phones, cable TV, student loans, car insurance, medical bills, saving for college for you, saving for vacation, then sometimes unexpected things can upset being able to pay regular bills, and that causes worry. It could be that your mother didn’t save up for the trip for your grandmother and used credit cards to pay for the trip, which your stepfather must now have to figure out how to pay out of the household budget. And perhaps your mother is too generous to your grandmother and sends her money that your family needs to pay its bills. Or perhaps your stepfather thinks she should be saving more for retirement so that when she is old, you will not be having to send her money.
In lots of cultures, children support their parents in their old age. Your mother wants to be generous to your grandmother, because she loves her and wants your grandmother to think that she is successful and be proud of her. Perhaps your mother is being a bit too generous with money that your family really needs to pay its own bills.
If your stepfather is the one to pay the bills, perhaps he is a good person to ask to explain to you how a family budget works. This is the one thing that if you learn to do when you are young, you will not get into money trouble when you are older. It costs a lot more money to run a family than kids are usually aware of. For example, my daughter’s friend got very upset that he did not get a brand new car for graduation. His grandparents gave his father a new car as a gift when he graduated from college. Instead of yelling at him for being ungrateful, his father took him car shopping. They went to the car dealer, the bank, and the insurance agent, and they figured out how many miles the boy drove. The cost of buying and maintaining the car the boy really wanted was about $750 a month, for 4 years. While his parents had saved up the cash for college, they had budgeted having to send him $300 a month out of income for expenses at college. That’s $300 a month they are not spending now, and if they were to spend another $750 a month for an expensive car, they would not be able to pay their regular bills.
While your mother’s money is her money, it’s also money that is needed to pay her own bills first. It can take two paychecks to run a household these days.