It's a bit messy this sentence.
Here's how I would interpret it;
For the length of time we knew one another
(could be each other also), (<comma) it was only until now did I find where she lives.
On its own looks like:
For the length of time we knew one another, it was only until now did I find where she lives.
To spice it up, instead of using Lives (as that's used in the middle of sentences more) could be to replace "where she lives" at the end of the sentence with "her place of residency". Also replace find with learn as essentially that's what you're doing.
For the length of time we knew one another, it was only until now did I learn her place of residency.
I'm sure there are many other variations which correspond to the way you structure the sentence and the context it is in.
But this confusion can be avoided when you use other structures, it may take longer but the result is clearer.
"We knew each other for awhile, but I never knew where she actually lived until today."