Yes, they can, but as a woman gets older, it becomes harder to get pregnant, but that's around 60 years old, so a 40 year old woman could get pregnant.
A 20 year old women has a chance of getting pregnant in the high 80's - close to 90%. By age 40 that falls to about 40%. - so about half the chances of a 20 year old. By age 45 it is about 5%.
It is possible. This would be dependent upon whether or not the woman has gone through menopause yet. If she is still ovulating, she can get pregnant. In 2008, a 70 year old woman gave birth to twins...