Refers to the senior nurse in charge of a ward or nursing unit. Note that 看護婦 is an older term for a female nurse; modern usage often prefers gender-neutral 看護師, making 看護師長 more common today.
She is the head nurse of this ward.
Modern, gender-neutral equivalent of 看護婦長. 看護婦長 is still understood but may sound dated or female-specific.
Compound of 看護 (nursing) + 婦 (woman) + 長 (chief). The term reflects the historical predominance of women in nursing.