unmotherly
/ʌnˈmʌðərli/Definitions
1. adjective
unlike a mother, especially in being cold, unkind, or unsympathetic.
“She was shocked by her unmotherly behavior towards her own children.”
2. adverb
in a way that is unlike a mother, especially in being cold, unkind, or unsympathetic.
“She treated her sister unmotherly and refused to help her with her problems.”