5 of the 10 most followed accounts on Instagram are for Kris Jenner's children

"Rank. User (followed／following)
1. instagram ( 14,500,399 / 221 )
2. kimkardashian ( 6,258,835 / 56 )
3. justinbieber ( 5,712,242 / 19 )
4. badgalriri ( 4,343,855 / 512 )
5. kendalljenner ( 4,190,510 / 166 )
6. taylorswift ( 4,052,116 / 9 )
7. iputthedistrictonmyback (Kylie Jenner) ( 3,527,104 / 149 )
8. khloekardashian ( 3,320,433 / 46 )
9. kourtneykardash ( 3,029,192 / 25 )
10. arianagrande ( 2,342,896 / 285 )"

Source:  Webstagram, retrieved 15th January 2013

According to Wikipedia, Kris Jenner has 6 children - Kourtney Kardashian, Kim Kardashian, Khloé Kardashian, Rob Kardashian, Kendall Jenner, Kylie Jenner.  Rob Kardashian is the 15th most followed account on Instagram