They say she's part Spanish, but her name sounds very Portuguese. What is the truth? And also, did you notice she is quite tall for a Filipino-Chinese-Spanish woman? 5'8 is an average height for a MALE of that extraction!
shareAccording to Tia Carrere's profile:
Heritage is "part Chinese, part Spanish, part Filipino."
So, she hasn't portuguese blood.
"Carrere" for me sounds italian, but being myself part italian I can tell you that "Carrere" is not an italian last name, at least I haven't heard it.
About her real surname "Janairo". It's not spaniard nor portuguese nor italian neither, although it sounds very "latino". looking briefly at google I've found several people named "Janairo", all of them from the Philippines.
Based on that facts this is my theory: The pinoys usually have spanish surnames since the Philippines were ruled by the spaniards almost for 400 years. But many spanish names were "slightly changed" with the past of time. So perhaps "Janairo" is a kind of corruption from an older spanish name (probably from Galicia).