Absolutely. As with all stories from the first age, the facts have become lost in the turnings of the wheel, but it is clear that Lenn did fly to the moon. Whether an eagle was involved is simply mixing up the story with other even older myths from the first age. Salya had plenty of help walking among the stars from her ability to weave Air to allow herself the ability to breathe even at great elevations.

From some sources I have managed to find, it seems plausible that Alsbet, the Queen of All, helped to send him to the moon in the fire eagle to save him from the anger of Mosk the Giant.

The only place for Lenn to be safe from Mosk was the moon, as well as the only way to safely escape the fire lance without Mosk's notice was inside the creature made of fire.

I have yet to find any substantial sources on Salya, or who her mother would have been.