A couple problems with this 1) There’s a Tagalog translation of sister (Kapatid or Ate), why not use that? 2) Sister could also be phonetically translated but would need to use modern Baybayin.

Below is a Kapatid (KA-PA-TI) and Ate (A-TE) in Baybayin.

Here’s sister (SI-S-TE-R) phonetically:

This is a classic example getting a Baybayin tattoo without the proper research or consultation. The fonts were obviously downloaded from the internet and translated using an online program. The end result is a tattoo that doesn’t make sense language wise or culturally. Unfortunately, I see issues like these rising due to the popularity of Baybayin tattoos.

Hanzi Smatter would be proud