Our potential relationships were arranged before we incarnated, and the tricky part is that our physical brains/minds were erased in the passage from the spiritual realm to the birth channel of infancy. I know that my W and I were intended to meet and marry, but the free will that each of us can exercise in this lifetime, allows for us to make mistakes, get confused, or find healing. And there is no predestined end result.
I have no problem with this line of thinking, but it does not mean her destiny in this lifetime is with you. The danger with this deterministic philosophy is that you can too easily fall into the trap that there is nothing you can do, it is all predetermined, and that you agreed in the otherworld to accept incarnation to a marriage that would end in divorce.
I do not believe that is how karma, reincarnation, and individual growth occurs. If you believe you are paying in this lifetime for mistakes you made before, then ask yourself why you were “allowed” to make those earlier mistakes in the first place. You made them because you could, because you had free will and exercised it (assuming you buy this line of argument). So you have free will now, and as the future is undetermined, you do not need to follow any script of prearrangement.
So even though I have faith that our marriage can be revived and become even better than it was, my W may choose to not truly see that potential, or may choose to do something that appears easier to her, like beginning a new relationship with someone else, rather than working hard on the one that we have been learning from together.
And you have the choice to do something to redirect the path she may choose. You do not have to allow the easiest path to be taken. You can affect her destiny.
BTW, what are her beliefs with regard to all this?