Travis Barker and Kourtney Kardashian both celebrated Penelope Disick's milestone 13th birthday with sweet tributes on Instagram.

Happy birthday! As Robert Browning once wrote, “Grow old along with me! The best is yet to be, the last of life, for which the first was made.” On this day [X] years ago, you came into the world.

Kris Jenner celebrated her granddaughter Penelope Disick—whose parents are Kourtney Kardashian and Scott Disick—turning 13 ...