Wis. Stat. § 769.302

A minor parent, or a guardian or other legal representative of a minor parent, may maintain a proceeding on behalf of or for the benefit of the minor's child. Notwithstanding s. 767.407 (1) or 803.01 (3) , the court may appoint a guardian ad litem for the minor's child, but the court need not appoint a guardian ad litem for a minor parent who maintains such a proceeding unless the proceeding is one for the determination of parentage, in which case the court or a circuit court commissioner shall appoint a guardian ad litem for a minor parent within this state who maintains such a proceeding or for a minor within this state who is alleged to be a parent, as provided in s. 767.82 (1) .