I think that you could argue this either way. It very much depends on how you see Draco's seventh year at school. When term starts Draco is one of several Death Eaters in the school and although his family seems to be suffering a little (with the loss of Lucius's wand) they are nominally supporters of the Dark Lord and playing host to Voldemort. Things don't really go downhill for Draco until he allows Potter to escape again! and that's the Easter holidays.Originally Posted by Sailing Girl
i can see Astoria being attracted to the swaggering Death Eater student in what must have been a terrible year for half-blood students.
Astoria started school two years after Draco, that puts her in the same year as Romilda Vane. Remember that Draco is at the younger end of the school year (a June birthday) so she could be 15-27 months younger than Draco. The Draco/Astoria age difference is almost the same as the Harry/Romilda age gap.
Alternatively, perhaps she's one of those ladies who fixates on dangerous criminals and she started to write to him while he was in prison. (This is an idea I might just run with.)