The mother of two took to Instagram on Monday, sharing a sweet family photo of the three in her home.
"Trig officially loves her #mybrotherhasmorechromosomesthanyou," Palin, 25, captioned the photo, adding a cat emoji with heart eyes.
In the photo, Trig holds the newest addition to the family, cradling her in his arms, as his older sister holds him and the baby close.
"My sweet Sailor Grace was born yesterday, our family couldn't be more complete," she captioned the photo with a double heart emoji.
Weeks after the new baby's arrival, Palin's ex-fiancé Dakota Meyer filed legal documents asking for joint legal and physical custody of baby Sailor, along with child support from Palin.
However, it didn't take long for Sarah Palin to hit back, defending her daughter and claiming that the former U.S. Marine is trying to "save face."
"For many months we have been trying to reach out to Dakota Myers (sic) and he has wanted nothing to do with either Bristol's pregnancy or the baby," she said. "Paramount to the entire Palin family is the health and welfare of Sailor Grace."