What is the fine-grained topic of the following text: Over a two-year period, Vincent's wife Tonya completed over 600 hours volunteering as a Girl Scout leader in elementary school activities and his three daughters, 13-year-old Angelina, 11-year-old Isabella and 8-year-old Sabrina collectively contributed over 1500 hours of volunteer service. Only return the topic.
Volunteer service by Vincent's family