Yes, I think your earnings from your business during the time of your marriage will be considered part of your communal assets. But it's best to consult a lawyer and confirm this.
*I'm not an attorney.
In most long-term marriages, the assets/debts will likely be split 50-50 and "long-term" refers to 10 years and above, so whether you are in the house physically or not during divorce proceedings should not matter.
The timing of your legal separation could affect the division of your marital...
Your girlfriend should be able to file for divorce anyway. The court could order for a divorce after several years of waiting despite the fact that her ex may refuse to sign the papers. It is best she checks with an attorney for the finer details. Good luck!
Yes, she will be able to keep the house, but I think it would be practical to wind up her divorce before she moves. It would be difficult to navigate the nitty gritty of it all from such a far distance. Perhaps she could move to a new place or stay with family/friends in the same city for now?