You should not be listing your mother’s boyfriend’s children on the FAFSA.
It is highly unlikely your mother is paying more than half the support of her boyfriend’s kids (he works and pays for their health insurance.) and they are probably splitting the household expenses.
Do they have a mom? Does mom provide any support for the children. You need to correct your FAFSA (especially since initial verification will come from the IRS).
The colleges are going to see it as the money that she spends supporting them, she will be expected to use to pay for you to attend college (as they are not her children or step children and their primary care should be provided by their parents).