The brief answer I can offer here cannot begin to encompass the whole of your situation and its history, although since I am based in Pittsburgh you are welcome to contact me "off list" to continue the discussion.
There is no such thing as "legal separation" in Pennsylvania. For purposes of divorce, actual separation is the benchmark, and separation is achieved by (for example) one spouse telling the other that their marriage is over, one spouse moving out of the shared residence, or one spouse serving the other with divorce papers.
As far as the divorce itself is concerned, since you have not yet been separated more than two years the no-fault ground we would be using is "mutual consent." If she declines to cooperate, as seems to be the case, the divorce process will be 'on hold' for a while. In case it helps, here is a link to an article on my professional blog that is relevant to your inquiry:
Before advising anyone simply to proceed with a divorce or suggesting what might be a good idea to do next, I would need to know more about your situation overall: for example, the economic circumstances of your marriage, the length of your marriage, whether you have children together, and what your goals are.
Right now, the two of you being separated, neither of you has any reasonable expectation of the other's fidelity. Both of you are free to date without inherently negative consequences in any divorce litigation.
Attorney Michael B. Greenstein
This response is offered for informational purposes only, does not create a lawyer/client relationship, and should not be taken as legal advice.
In Pennsylvania, there are both fault and no-fault grounds for divorce. In short, in order to get a no fault divorce both parties have to sign an affidavit of consent which can be filed 90 days after the compliant was filed or be seperated for a period of two years. The seperation period can begin while you are still in the same house if for example you are living in seperate bedrooms.
Based upon what you state above you may have fault grounds (such as adultery) which would allow you to proceed if your ex is unnwilling to sign the affidavit of consent and do not want to wait two years. Fault based divorces are more expensive because the fault ground has to be proven in court.
It sounds as if you have already filed the divorce complaint, so if fault based grounds were not included you may be stuck waiting the two years to be able to proceed with a no fault divorce without your ex's consent.
Hope this helps and good luck.
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