Only Daughter
noun
An alone (一人) daughter is a daughter with no other daughter siblings, making her the only daughter.
The readings are 一人 plus 娘 put together into one, single (daughter) word.
クララはゼーゼマン家の一人娘です。
Klara is the only daughter of the Sesemann family.
彼には一人娘がいます。
He has an only daughter.
林さんは女手ひとつで一人娘を育てています。
Ms. Hayashi is raising her only daughter by herself.