Regarding your son:
A parent may qualify as a dependent if their gross income doesn't exceed $4,700 (tax year 2023) and the support you provide exceeds their income by at least one dollar during the tax year.
• Social Security income generally doesn't count toward your parent’s gross income, but there are exceptions, such as when your parent has other income from interest or dividends.
You must have provided more than half of your parent's support during the tax year in order to claim them as a dependent. The amount of support you provided must also exceed your parent's income by at least one dollar.
If you paid for more than half the cost of maintaining a home as your parent's main home throughout the entire tax year and you are eligible to claim them as a dependent, then you may be able to file as head of household.
Reference links: https://turbotax.intuit.com/tax-tips/family/steps-to-claiming-an-elderly-parent-as-a-dependent/L34je...
https://turbotax.intuit.com/tax-tips/family/guide-to-filing-taxes-as-head-of-household/L4Nx6DYu9
