A person who is married and filing a separate return can still be claimed as a dependent by their parents for tax year 2024 if they live with the parents, the parents provide over half of their support, and the dependent doesn't have income of over $5,050 unless they are a full-time student under age 24. See this TurboTax tips article for more information.
You may wish to contact the US Department of Veterans Affairs to determine the benefits for which your partner qualifies and if they are affected by changing marital status. See this VA webpage for more information.
@Chelseyl1805