The Turning seems fairly recent in "To Rebuild the Eyrie". Mouse's father Yareth is young and in "Falcon Magic" the other Falconer (forget his name) is constantly putting him down. I believe Yareth may have had his initial training in the Eyrie & got his falcon there before the evacuation and the Turning (probably around 11-13 yrs old going by the ages of the kids in "Falcon Law"). The bit which implies Yareth was too young to remember the Eyrie was just an insult by that older, misogynistic Falconer. Yareth doesn't refute that because he doesn't counter ANY of the other Falconer's insults. I believe the earlier date for Mouse's birth is the correct one and the later date can be "retired".
The only other argument for Yareth being too young to remember the Eyrie is a note by the author at the end of the story, otherwise I would agree that the earlier dates are likely more 'correct'. They certainly fit in with the timeline better.