There is a cultural issue here, which in part explains the couple's desire for children, but not the ethical responsibility of providing the means for them to achieve that desire - both financial and medical.
I have always believed that children are a gift, not a right, and I do not say that lightly. I was sad enough that we were unable to have a fourth child, but delight in the three we have, and accept my extreme good fortune.
I know that nature provides a 'cut-off' point for a very good reason - the simple physical strain of caring for growing babies and children. I am a 'young' grandparent, and my gradchildren wear me out, which is fabulous, because they return home while i recover - if this was 'home', then I never would!
To return to your Question - I think the mother knows that her time with her child(ren) is short, but the cultural pressure is such that it makes the situation worthwile for her.
The same cannot be said of Western women exercising what they believe is their 'right' to have a child far too biologically late in life.