The Bible does not say directly. She was though, a widow with two dead sons (Ruth 1), and both of these sons were old enough to be married, because Ruth and Orpah were their wives. She said in Ruth 1 also that she was too old to take another husband.
So while there was no age given, she was... old.
Naomi Knight is 30 years old. She was born on November 30, 1987.
Naomi Wilkinson is 43 years old (birthdate June 30, 1974).
Naomi Uemura is 69 years old (birthdate: February 12, 1941).
Naomi Robson is 49 years old (birthdate: December 4, 1961).
Naomi Wolf is 55 years old (birthdate: November 12, 1962).
Naomi Kawase is 42 years old (birthdate: May 30, 1969).
Naomi Klein is 41 years old (birthdate: May 8, 1970).
Naomi Scott is 24 years old (birthdate May 6, 1993).
Naomi Scott is 17 years old.
Naomi Biden was around one year old when she died.
As Naomi was a widow and old, and Ruth was also a widow she stayed loyal to Naomi.
Naomi Shihab Nye is 59 years old (birthdate: March 12, 1952).