Hadid, 18, whose big sis is Gigi Hadid, lounged by the pool with her mother – both wearing matching one-piece swimsuits – in the new photo shared via Instagram Saturday.
Both models (Foster former, Hadid current) leaned their backs toward each other in low cut suits, each in a different shade of red.
In the background of the crystal clear pool are palm trees and well groomed shrubbery.
"Mommy n meee day," wrote Hadid. "Home is when I'm with you."
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Foster, 51, has been very publicly battling Lyme disease over the past few years. After being diagnosed in 2012, the former model launched a social-media campaign dubbed #LymeDiseaseChallenge, which asks friends to share images of themselves sucking on limes to spread awareness about the chronic disease.