The way I read it she must have been a resident here for 15 years, prior to be excempt. This is taken of the ins naturalization guide.
Applicants for naturalization must be able to read, write, speak, and understand words in ordinary usage in the English language. Applicants exempt from this requirement are those who on the date of filing:
have been residing in the United States subsequent to a lawful admission for permanent residence for periods totaling 15 years or more and are over 55 years of age;
have been residing in the United States subsequent to a lawful admission for permanent residence for periods totaling 20 years or more and are over 50 years of age; or
have a medically determinable physical or mental impairment, where the impairment affects the applicant’s ability to learn English.
