I'm normally in the chloe forum but am looking for a more practical bag. I'm about 5'5' and weigh about 50kgs so I really want to get the right size speedy for my frame. I've seen some speedy 25's and they look a little small, so perhaps a 30 then? I remember seeing Heidi on the hills with a speedy which looked to be the perfect size - anyone know which it was? Thanks!