Frustrated and depressed ?

Survival of the species is the strongest instinct in all of us. It is no wonder you are not conceiving with so much stress going on. Is there no other brothers or sisters that could take the sister-in-law. You have every right to want to have your own child. Your sister-in-law is not a child substitute. However, it would be appropriate for you to consider her a sister. It must be very hard for her also to live in a different place after losing her parents and not understand what is expected of her now.