Kammala jumla mai zuwa: An haifi Sarah Asher Tua Geronimo a ranar 25 ga Yuli, 1988, a Santa Cruz, Manila, Philippines zuwa Delfin Geronimo, wani ma'aikacin PLDT mai ritaya, da Divina Tua, wanda ke gudanar da gidan gyaran gashi a gidansu. Ita ce ta uku a cikin yara hudu. Ta fara raira waƙa a bainar jama'a tun tana 'yar shekara biyu. Lokacin da take 'yar shekara hudu, mahaifiyarta ta raka ta don shiga cikin shirye-shiryen talabijin daban-daban. Geronimo ya zama wani ɓangare na nunin "Penpen De Sarapen" (shekaru 4-6), "Ang TV" (shekaru 7-8) da "NEXT" (shekaru 8-9). Ta kuma taka rawa a matsayin karin a cikin fim din "Sarah... Ang Munting Prinsesa" (1995). Tsakanin gwaji, Geronimo zai yi aiki a wuraren cin kasuwa da wuraren shakatawa na otel. Geronimo, sa'an nan shekaru 7, ya kasance daya daga cikin masu wasan kwaikwayo a lokacin
1995 ziyarar Paparoma John Paul II. Geronimo tun yana ƙarami ya shiga gasa daban-daban na waƙa wanda na farko shine Tuklas Talino wanda Kamfanin Wayar Philippine Long Distance (PLDT) ya tallafawa.