Hello there!
Kristine Hermosa is Filipino because her nationality is Filipino.
Mestizo in the Philippines is not a mix of Filipino or Spanish blood, but a mix of MALAY and Spanish blood, there is no such thing as having "Filipino blood" because there is no such thing as a Filipino race, there is a Filipino people made up of the mixture of several races: MALAY, Spanish, and Chinese ancestry making up the ancestry of the majority of Filipinos. (not "Filipino", Spanish, and Chinese ancestry)
After the Aeta natives who are thought to be related to the aborigines of Australia, the Malays immigrated to the Philippines and make up the majority of it's stock, then a very large ethnic Chinese population, then Spaniards arrived and settled and intermarried with the native Malays and ethnic Chinese, and mestizos were born of the main three ancestries that today make up the culture and ancestry of modern day Filipinos.
The word "Filipino" is originally a Spanish word originally used to refer to the Creole Spanish population of "Las Islas de Filipinas" (the original name of the country named after King Felipe II of Spain), after the Philippine Revolution, it was extended to include anybody born in the Philippines, not just Filipinos of mostly Spanish descent, but the mixed race mestizos, the Malay, and the ethnic Chinese. Anybody born in the Philippines who identifies with the national culture is a Filipino, regardless of their ancestry.
Many Filipinos are miseducated due to the way history is taught in the Philippines, and often mistakenly refer to someone as being of mixed "Filipino and Spanish blood" or mixed "Filipino and Chinese blood" when they really mean to say mixed "MALAY and Spanish blood" or mixed "MALAY and Chinese blood", Filipinos often substitute the word "Filipino" to refer to the native Malay population due to the grand miseducation that takes place in the Philippines' school systems. This leads to a lot of confusion by non-Filipinos, and Filipinos who aren't properly educated about their own country, about the ancestry of Filipinos. It leads people to believe that Filipinos are a seperate race unto themselves, when in reality, Filipinos share the same Malay and Chinese racial ancestry as the rest of Southeast Asia. The only difference between the Philippines and the rest of Southeast Asia would be the Spanish ancestry of Philippines. And it's not only 2% as Wikipedia says, that was info based on texts originally written and edited by uneducated Americans who arrived in the Philippines in 1902, colonized the Philippines, and didn't understand how race was categorized in former Spanish colonies and based it on their own "half-breed, pure White, etc." system, just do a little more research, read books that describe the written history of the Philippines in SPANISH instead of in English (written by mostly uneducated Americans who applied their own views of race to the Philippines and categorized people according to how they viewed it, which we know is drastically different), because it was actually written by those who were there during the 300 years and don't rely on that rubbish of an "encyclopedia" called wikipedia, hehe

Mestizo is an outdated term, not only in the Philippines, but in the rest of Latin America and all of the Spanish-speaking countries, because it's difficult to actually trace racial ancestry these days after hundreds of years of racial mixture.
But many Filipinos unfortunely continue to use it, in perhaps an uneducated manner due to the uneducated manner the school system teaches it (which has it's roots in American colonization) which contributes to non-Filipinos' confusion about the actual ancestry of the people of our country.