Here's why that's likely:
* "Full House" is a complete series: The original "Full House" aired in 2004 and was a very successful drama. There is no official sequel planned.
* Song Hye Kyo is a big-name actress: She is known for her selective choice of projects and typically takes on roles in high-quality dramas with strong scripts. It's unlikely she would choose to return to a series that is already considered complete.
However, the entertainment industry is full of surprises. If there were to be a new drama loosely based on the "Full House" concept, it's possible that Song Hye Kyo could be considered. But, for now, there are no concrete plans for a "Full House 2" with her involvement.