You may amend MFS to MFJ, but both spouses must agree.
Also, you say your wife has "issues". You should know that by filing a joint return, each spouse is jointly and severally liable for all income, deductions, facts, errors, omissions or other problems with a joint tax return. If a problem is discovered, the IRS can come after either one of you, or both, or only you, if you have more money or are more easily collected from, even if the error is entirely your spouse's fault. Filing a joint return ties your finances together forever, at least for the year you file (2023, in this case). However, with separate returns, you are not responsible for errors or omissions on your spouse's return, even if they are intentional. Depending on what the "problems" are, it might be wiser to pay the extra tax and keep your returns separate.
