It is not always a good idea to translate words separately from sentences.
1) Particle -то has nothing to do with animate/inanimate.
2) -то added to relative/interrogative pronouns makes indefinite pronouns as like as in English adding "some...":
кто - who, кто-то somebody
где - where, где-то somewhere
почему - why, почему-то - for some reason
etc.
3) with other words -то has a meaning of emotional emphasis and is used in colloquial speech.
4) In your example "наш" is used as adjective "тихоня" is a noun and "-то" adds some emotional coloration.