Illinois does allow a married couple to file separately for the Illinois state return regardless of how they file their federal return. The process in not easy when using TurboTax software.
HERE is a TurboTax link explaining how it's done using TurboTax.
Basically you need to make a mock federal return in TurboTax for you as single, then the Illinois return will only pick up your information and compute a Married Filing Separately State return.
Disregard the mock federal once the state is done.
You won't need to make a second mock federal report since there won't be a need for a return for Florida.
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