Eugene van der Pijll
He doesn't count as a Family Member for scoring or any other purpose.
Quoting from the Unofficial Agricola Compendium, v6 (not released yet):
The guest worker does not count as a family member for scoring or for the Ratcatcher, Midwife, Barbecue, or Family Portrait, but its action does count for the Church Warden.
Playing the Guest Worker is not a family growth action.