Gigi Hadid Always Makes Sure Bella Is Behaving Herself

Bella Hadid shows off her toned abs as she makes her way through Heathrow Airport on Friday (September 16) in London, England.

The 19-year-old model was definitely on her best behavior at the airport because her sister Gigi checked in to make sure!

PHOTOS: Check out the latest pics of Bella Hadid

“Whether on set or at the airport I always check to make sure my lil siblings are behaving themselves ;)” Gigi wrote on her Twitter.

She added, “Today a lady at Check-In said @bellahadid was her favorite passenger today!! It made me very emotional. ✈️😄😭😄😄😇�’� #PROUDSISTERVIBES”

20+ pictures inside of Bella Hadid at Heathrow Airport…