In case you missed it, just LOOK at how cute Kylie 2.0 is!
While Kylizzle's super brief caption was V. cute, it doesn't quite help us in the last name department.
If she follows in the footsteps of big sisters Kim and Kourtney Kardashian, she will probz go the traditional route and give the baby her Dad's last name, just like Penelope, Mason and Reign's last names are Disick after Scott and North, Saint and Chicago's last names are West after Kanye.
So that would make Stormi's last name Scott, right?
It turns out Travis Scott is the rapper's stage name, his real last name is Jacques Webster. Who knew!?
So it's likely that the pair will either choose to give Stormi the last name of Webster or possibly even hyphenate it so that it's Webster-Jenner.
As with everything Kar-Jenner related, all will be revealed in time...