My aunt needs a birth certificate, she is about 55-62 yrs old, she has never known her birthdate.?

The mother had many children and didnt remember where Angie was born. My aunt has never known her birthday. After over 30 years of marriage her husband past away several years ago. She cannot collect his pension, she never even had a social security number. She has tried to look up the information many times over the years and never could find her Birth Certificate. Now that she is older she really needs to resolve this.