Middle-aged or old?

Our oldest has a wife and baby. One daughter is married with two children and another is engaged. The third is in her first year at uni, but we still have two more at home with some years of school to go. That means we still claim child benefit. We support the one at uni and anticipate having to find university fees for the two youngest. So we thought we were middle-aged, middle-income, middle-class.

However, Adrian found the age-related heating allowance in his bank account, so perhaps we've already moved into the old age bracket.