I don’t know. I had a similar thing happen to me with a pair of shoes from Zappos. They were supposed to be delivered to my son at college, but they never got there. When I tracked them, it said they went to the right street address but the wrong town. Zappos started a trace with UPS, and UPS eventually called me and told me where they’d been delivered. In this case, it was his mom’s house (they looked up his name and found it associated with her address), but they didn’t know that before they told me.
Having prosecuted several of these cases over the years, I strongly suspect it was not an innocent mistake by the sender of the package, Fed Ex did not make a shipping mistake, nor did they have to call Fed Ex. One would wonder whether Fed Ex would even have a record of the call if one were made, and I really doubt the guys in the driveway will be “available” as witnesses for her.