11 Abraham and Sarah were already very old, and Sarah was past the age of childbearing.

Read Genesis 18:11 Using Other Translations

Now Abraham and Sarah were old and well stricken in age; and it ceased to be with Sarah after the manner of women.
Now Abraham and Sarah were old, advanced in years. The way of women had ceased to be with Sarah.
Abraham and Sarah were both very old by this time, and Sarah was long past the age of having children.