I am afraid you have twisted a little bit. If according to your logic, Simple Past "I ate dinner" is also not a finish, because I will eat dinner also tomorrow.But perhaps, she will visit the Ocean Park also in the next years. That's why it is (in both examples) not finished.
Most, if not all, agree that Ex1 is a finish. Mary has finished an amount of visitations.
The question is, in Ex2, how does Since link the visits to the present?