I think you can keep up with your child just fine if you have the child at 40 (your timeline - 31+9 from the OP). But, you may not be physically able to produce quality eggs by then due to the family history. That is why freezing them now would be a good idea - not to be un-romantic, but just to preserve the options. Also, if I understand correctly, women after age 35 are more likely to conceive a child with the Down syndrome, which is why freezing eggs before 35 and using them after 35 might be smart.

But if this is out of financial reach, then sure there is no point in discussing this option.