You may have to include your spouse's income because you may have to file a Indiana tax form IT-40PNR. However, this does not mean that your spouse's FL income will be taxed by IN.
The following information comes form the Indiana Department of Revenue website which can be accessed here Indiana Department of Revenue IT-40PNR Booklet
Form IT-40PNR for Part-Year and Full-Year Nonresidents
Use Form IT-40PNR if you (and/or your spouse, if married filing jointly):
• Were Indiana residents for less than a full-year or not at all, or
• Are filing jointly and one was a full-year Indiana resident and the other was not a full-year Indiana resident, and
• Do not qualify to file Form IT-40RNR.
Form IT-40RNR for Full-Year Residents of Reciprocal States
Use Form IT-40RNR if you (and your spouse, if married filing jointly) were:
• Full-year residents of Kentucky, Michigan, Ohio, Pennsylvania or Wisconsin, and
• The only type of income from Indiana was from wage, tip, salary or other compensation*.
*You are required to file Form IT-40PNR if you have any other kind of Indiana-source income.
Based on the above information, it would appear that you may not qualify to file Indiana Resident/Non-Resident return, and thus will need to file the Indiana Part-Year and Full-Year Non-Resident form.
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