We have a little sister, and she hath no breasts: what shall we do for our sister in the day when she shall be spoken for? We have a little sister - This young girl belonged most probably to the bride.
She hath no breasts - She is not yet marriageable.
What shall we do for our sister - How shall we secure her comfort and welfare?
In the day when she shall be spoken for? - When any person shall demand her in marriage.