Thanks for your question.
Of course she need not sign the divorce petition in order for you to submit it to court but she will need to acknowledge it in the case of unreasonable behaviour or adultery. Her consent is required in the case of petition on two years separation.
If you wife will not consent to a divorce petition based upon the fact that you have been separated for two years then your options are to petition either on the basis of adultery, unreasonable behaviour or wait for a further six months before petitioning citing a five year separation (for which you are no doubt aware that her consent is not required.
If you think that she will defend a divorce in open Court a petition based upon unreasonable behaviour and you do not wish to go through the stress/expense of this (ie. the airing of your dirty laundry in public so to speak) and there is no adultery then waiting for the five year separation is your only option.
If you think that she will not defend a petition based upon unreasonable behaviour but may not acknowledge the petition then you could issue a petition based upon unreasonable behaviour and have it personally served upon her by a process server that the the divorce may then proceed.
The key issue with unreasonable behaviour is whether you believe that she will defend and you willingness (or not) to proceed on a defended divorce. Such divorces are very rare, expensive, time-consuming and stressful.
If your wife has committed adultery then you could petition if this is admitted. If it is not admitted then this must be proved either by birth of a child or circumstantial evidence.
Periods cohabitation can affect your eligibility for a divorce.
The path of least resistance is a divorce petition based upon 5 year separation but if you cannot wait another 6 months then you should consider the above.
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