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Your spouse is applying for a Schengen tourist visa for France and you are sponsoring and paying for their trip. Since you are sponsoring the trip then you must show the proof of sufficient funds and of their provenance. Your documentation should demonstrate that you have enough funds for the entirety of your spouse's trip. For guidelines on how to do this please see our canonical Q&A for UK visas.
You could show your spouse's bank statements, provided these help your case. An empty bank statement provides no information. On the other hand a bank statement showing regular money deposits from you to be intended as, let's call it, "allowance" made over a period of several months can help in upholding your spouse's proof of sufficient funds.
Regardless of who is sponsoring the trip, your spouse will have to demonstrate that they are honestly wishing to visit France for tourism and not for other purposes (looking for a job, settling down, doing business, etc.). This is done by showing strong ties to the UK which allow the immigration officer to gauge the likelihood of her returning there once her trip to France is over.
Being married to someone living in the UK is one such strong tie. Conversely, being unemployed is a weak tie. The idea is to show that your spouse has commitments in the UK which would justify the fact that they are not trying to overstay in France.