DS-157 - Clarification

[easwara]

My mom is born in Jan 24th 1952. When I booked the appointment it did not ask for DS-157 form.
But it's just the statement confusing about the age. Is this form needed for the applicant who is below 55 years or till 56 years.

[immihelp]

She is still 54. DS-157 is required.