She may have just tried to be supportive, since this job was important to you. She may have looked at it as a break from another needy person in her life when she only had so much to give.
Don't beg or plead, but if you're truly sorry about leaving her when she needed you, you should tell her.
I don't know if it will help at this point, since you have another 10 months left on your assignment, but it may at least show her that you get that you were being selfish and are remorseful.
