Ginny as an accidental Horcrux

[Mary]

No: HPFGUIDX 156897

My teenage son came up this theory recently and I find it intriguing, 
especially as a possible sequel to JK's 7 book series.

In COS, Tom Riddle says to Harry,"..to put a little of my soul back 
into her." 

We know that the part of Voldemort's soul that was in the diary was 
destroyed when Harry pierced the book with the Basilik's tooth. The 
question is: was all of the soul that Tom put into Ginny sucked back 
into the book or Tom? Could any of it been left behind in Ginny? 

It's an interesting thought because this would be a "second generation" 
horcrux, that of the Tom Riddle/prefect stage of Voldemort's character. 

Any comments or ideas?

---Mary