First sign of spring?

Last fall, a couple of caterpillars pupated in a jar in my kitchen. I put a lid on it and hid it in a quiet corner. Yesterday morning, the jar contained a brand new butterfly.

Cabbage white butterfly, Pieris rapae. Female, because she has several spots on her forewing. Males have only one.

She's getting ready to leave.

I had to climb up into the kitchen sink to get these photos. A minute later, she'd moved on. I haven't been able to find her since, so she'll have to stay inside.