My wife and I married but her parents filed for her as dependent to them, and i want to file my taxes separately from hers', what should i do?

[JohnB5677]

Yes, You may be able to do it exactly as you stated!

You and your wife can file Married Filling Suberate at any time throughout your Marriage. 

• Be aware, you are not filling Single, you are filling Married Filling Separately. See Filing Status.  
• If your wife requires a tax return she will file the same.

Her parents can still claim her as a dependent.

• If she is under 19 at the end of the year, she may be a Qualifying Child.
• Or she may qualify as a Dependent relative.
  • The relative must live with her parents all year as a member of your household.
  • She must earn less than $4,700 in 2023. 
  • Her parents must financially support her.
• In all cases, to claim someone as a dependent on their tax return, Your wife can not be claimed as a dependent on anyone else's return.

Also please see: Rules for Claiming Dependents on Taxes