Possible? Well, nobody knows when your grandfather is going to die.
* He may surprise all his family and reach his 100th birthday giving enough time to George Lucas to reconsider his position and develop / film another triology. 22 years is more than enough.
* Or, your father may die before anyone convince GL to film more Star Wars Episodes,
Who knows?
Plot for 7?
* There are plenty of novels written in the Star wars expanded universe to choose.
* Most fans say the best option is the Thrawn Trilogy for Episodes VII, VIII and IX.
The Thrawn Trilogy, also known as The Thrawn Omnibus, the Zahn Trilogy, the Empire Trilogy, The Three-Book Cycle, and the Star Wars cycle consists of three novels: Heir to the Empire, Dark Force Rising and The Last Command. They were written by Timothy Zahn and take place about five years after Star Wars Episode VI: Return of the Jedi (i.e. in 9 ABY.)
If not the Thrawn Trilogy, then jump a group of years later and start a triology with the kids of Han Solo & Leia Organa, and the ones of Luke Skywalker & Mara Jade already as Jedi's. But Mara Jade character is introduced in the Thrawn Trilogy, inserting her and her kids now, without her background as a "Hand" of Palpatine in the Thrawn Trilogy would be odd.
===
If you are a SW fan, you will not trust information in the supershadow website. Go to starwars .com; the force.net or even wookiepedia for easier search.