MFS to MFJ

I have a client - couple filed MFJ in 2023.  Husband was listed as taxpayer.  For 2024 the wife decides to file a MFS return through Turbo Tax. She has already received her refund.  (She just wanted to get her refund early.  No other reason for filing separately) Husband gives me his W-2 (All they have are 2 W-2s and standard deduction).  His income is over $250K.  Hers is under $16K.  By filing his return as MFS, he owes over $23K.  If we file MFJ, he owes under $7K, saving them $16K.  So - how do I do this?  I thought maybe I could file a superseded return as MFJ, but the software says I cannot efile a superseded return when the original return was not successfully efiled.  I don't want to file MFS for the husband and have him pay in all that tax, just to amend and get it back.  They live in Florida, so there is no State tax to worry about.  Can I file an amended return for her showing all zeros and have her pay back her refund and then show both on an original MFJ return? Any thoughts or suggestions?