A mathematician is invited to family dinner. When he meets the family of four, he is intrigued to know the wife age. When asked, the wife responds "If you add the age of all family members you will get 100. My husband's age is equal to th squares of my son's age added to the square of my daughter's age added to the square of my age. My daughter is a year older than my son." Supposing the wife is the second eldest in the house, what is her age?