You say that "I [you] get this," but your post seems to prove otherwise.
In all 6 classifications within the PIAA, there are 32 teams that make States. The number that make it from each PIAA district are based on the number of teams in that district that play at that classification, and the total number of teams in that classification across the state. It's actually quite fair.
In Class A (smallest schools) girls, D1 gets 3, D2 gets 0, D3 gets 6, D4 gets 4, D5 gets 2, D6 gets 3, D7 gets 5, D8 gets 0, D9 gets 4, D10 gets 2, D11 gets 2, and D12 gets 1
In Class 6A (largest schools) girls, D1 gets 11, D2 gets 1, D3 gets 7, D4 gets 0, D5 gets 0, D6 gets 2, D7 gets 5, D8 gets 0, D9 gets 0, D10 gets 0, D11 gets 4, D12 gets 2