The photo showed the 56-year-old singer lying on the floor while David and Mercy kneeling in front of her and rubbing her feet.
"#motherlove.. How I'm gonna get through the day. Mercy and David give the best foot rubs!!! #rebelhearts," she captioned it.
Some Twitter users slammed Madonna for posting the picture, accusing her of treating her adopted children like slaves because they're black.
Wendy Williams reposted Madonna's pic along with caption, "HOT QUESTION: Are you offended by the photo Madonna posted?"
@HolyJaxon tweeted, "Wow @ madonna hiring slaves."
@stillOJ posted, "Madonna adopted some slaves from Africa. TELL ME HOW ITS DIFFERENT." @emxlio added, "Madonna getting served by her slaves.