Why do you think the series came to an end?
I think there was a cloud hanging over the seventh season, especially in the beginning. I don’t think anyone was sure what Sarah was going to do, but I think she decided that seven years was enough.
She’d just got married and I think she wants to have children relatively young. She wanted to spend time with her husband and explore other opportunities, primarily in film. I’d imagine she’ll make guest spots on Angel from time to time, to keep people happy until the Buffy movies start coming out.