Breishit 23:1 mentions that Sarah was 127 years old when she died. Ohr Hachaim's commentary seems to glance upon some issues regarding why Sarah's age was mentioned, and he seems to focus on the fact that she suffered the biggest challenge because she didn't give birth until she was 90.
The commentary mentions Rachel who also didn't give birth until later in life. I saw no mention of Rivkah (though it may be there).
I agree that not giving birth is severe suffering, but there were many women in Tana"ch that had trouble with birth. Chana and the Shunamite woman (mentioned with Elisha) are two examples outside of the Torah. None of these women had their ages mentioned when they died. As a matter of fact, their deaths aren't even mentioned!
It seems that it was only because of the length of Sarah's birth suffering that she seems to be the only woman in Tana"ch to have her age mentioned at death? Why would that factor alone make Sarah noteworthy?
Sarah seems to be the sole exception to this rule as she seems to be the only woman having her age mentioned at death. Why is she the only exception?