If you use the FSA and your spouse never finds work, then your use of the FSA will not be qualified. The amounts will be added back to your taxable income (as if you never had the FSA) but there is no additional penalty. If she does find work, then the money you spend would be qualified and would be eligible for tax exclusion. But if you put money in the account and never spend it on care, then it is simply forfeit. And there aren't any tricks or loopholes to get around that.
