A member who qualifies for a disability allowance under this chapter and who has attained age 45 years, but who has not yet attained age 60 years, shall have his or her allowance calculated upon service with each year of credited California service providing 5 percent of final compensation. The disabled member shall receive the lesser of this amount or the amount provided by Section 24006. A child’s portion of the allowance shall be determined pursuant to Section 24006. This section shall not apply to a member who is eligible to apply for a disability allowance under subdivision (c) of Section 24001.