Dear Ms. Doromal,
Thank you for posting your request on History Hub!
Even though most documents from 1932 to 1945 were destroyed in World War II, you may wish to request a search from the Philippine Statistics Authority, which has custody of the major civil records after 1932, including birth records. We also suggest that you search the Philippines Civil Registration (Archives Division), 1902-1945, and the Philippines, Manila, Civil Registration, 1899-1984 for the birth records of your mother. In addition, the FamilySearch Research wiki for Philippines Civil Registration- Vital Records may be helpful.
We hope this is helpful. Best of luck with your family research!