Mid 16th century (in an earlier sense). In sense 1 from nursing + mother, after Hebrew mēneqeṯ wet nurse, foster mother, use as noun of participle of hēnīqāh to nurse, suckle, breastfeed from yānaq to suck; compare nursing father.
Definition of nursing mother in US English:
nursing mother
nounˈnəːsɪŋ ˌmʌðə
A mother who breastfeeds her baby.
Origin
Mid 16th century (in an earlier sense). In sense 1 from nursing + mother, after Hebrew mēneqeṯ wet nurse, foster mother, use as noun of participle of hēnīqāh to nurse, suckle, breastfeed from yānaq to suck; compare nursing father.