Dominique Weasley is the middle child of Bill & Fleur Weasley (YL).
Mother: Fleur Delacour (1997-)
Father: Bill Weasley (1970-)
Siblings: Victoire and Louis Weasley
While fans assume that this child is a girl, and that does seem likely, there is nothing in canon to verify gender. The name is actually unisex and could belong to either a boy or a girl (Dominique on babynames.com). A notable example of a male with that name is Dominique Wilkins, a professional basketball player.
Even Pottermore's artists make this assumption, as shown in the Weasley Family Tree they posted.
Tags: second generation