Mama June Takes Custody of One of Chickadee's Daughters After Cancer Death

Mama June is taking over mama duties for one of her late daughter Anna "Chickadee" Cardwell's kids ... TMZ has learned.

Family sources tell TMZ ... Mama June is currently in custody of Anna's 11-year-old daughter Kaitlyn.

Anna, who died Saturday after a difficult battle with cancer, had 2 daughters with 2 different men ... and our sources say the younger child, 8-year-old Kylee, is now living with her biological father, Michael.

We're told the family had a plan in place for Kylee to move in with her dad should something happen to Anna, who was diagnosed, back in January, with stage 4 cancer.

Our sources say Kaitlyn and Mama June have a very close bond -- she's June's first grandchild -- so, everyone in the family agrees, moving her to Grandma's house is the best situation for her. We're also told June plans to become Kaitlyn's legal guardian.

As we first told you, Anna secretly married her partner, Eldridge Toney, back in March after learning she had cancer.

We're told Eldridge has a very close relationship with both Kaitlyn and Kylee -- though he's not their biological father -- and he will continue to be involved in both their lives as well.