If you are filing a divorce against her, you can plead mental cruelty and then, at the time of the divorce, amend the grounds to irreconcilable differences in addition to your wife signing a waiver of the two year waiting period.
For irreconcilable differences, you must be separated for a period of 6 months, and must sign a Waiver of the Two Year waiting period. For mental cruelty (and most other grounds), there is no required period of separation.
Although there is a required separation period (at least six months), it doesn't necessarily mean you have to be living in different residences. Illinois courts have defined "separate and apart" to include living under the same roof but as if you were living separate and apart.
So, if your wife moved back in for financial reasons, you may have a good argument that you were still separated during this time. If this is the case, and you considered yourselves separated despite being in the same household for the past year, you could write in that you have been separated for three years.
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