Actually wingercizing doesn't begin until they have flight feathers ... at this age they are using their wings to balance themselves and to help them move around, next they will actually be able to get up on their feet properly and waddle about but until then, their wings help them out.
And yes, first fledges are on average about 45 days but males will go first and females last, up to a week between the genders or not. We'll know when they are going to fledge by their behaviour ... and lots of serious wingercizing