I love Peggy ... I'm probably influenced mostly by a girl I grew up with (she was my older sister's age) who was unusually named Peggy, and the song "Peggy Sue." I don't think it's dated because I have never known any other Peggys except this one girl, who was really nice, smart, tall and pretty... in fact she was my sister's best friend & also her rival.
Teddy, on the other hand, does seem dated to me ... although about the right date to be fashionable rather than frumpy.