I know where she lives in is an unusual sentence, because normally the meaning of where includes a sense of place that's supposed to have any spatial prepositions already "built in"; phrases like on the hill or in the house are answers either to the question where or to what on/in, not to *where on/in.
I know where she lives around is a reasonably common kind of thing to hear, so is where through, and where at has currency in the vernacular, so I wouldn't be surprised to find out some people are using where in in a similar way, especially if trying to emphasize that the location will be of the form in X. But even if that's the case, there's no way that use is common enough to be viewed as standard.
I can also easily picture the phrase to live in being used with the meaning "to be a live-in domestic servant" (though I've never witnessed this use) but in that case I'd expect it to be hyphenated: I know where she lives-in.
Where to and where are both common ways to refer to a motion's destination, but where is somewhat ambiguous, as it can also mean a location that contains the entire motion.
(We also have the unambiguous word whither, but obviously that one is musty enough to heavily mark the style.)
Most importantly of all:
By broad consensus, stranded prepositions in English are fine, and have been fine since before Shakespeare. The common objections against them were a fashion of over-regulation that sadly still persists here and there, especially in the education system, but I can't remember any modern grammarian arguing against it.
