(another person's) younger sister
Honorific term used to refer to someone else's younger sister politely. The reading いもとご is a less common variant.
See also: 妹さん (いもうとさん)
How is your younger sister doing?
I hear his younger sister will graduate from university next year.
Standard kanji spelling for this honorific term.
Compound of 妹 (いもうと, 'younger sister') and the honorific suffix 御 (ご).