Did Legolas have any brothers or sisters?

[zifnab]

!throw The Silmarillion Bêthberry

How could you forget Feanor?

I would 'assume' that Elves cherish their family tree, relishing their heritage (always an exception of course). And most would not hold back in relating this fact to non-knowing others. Since Legolas and Thranduil never made mention of another child/sibling it was either not easily relatable to the story, not important enough to further the plot, not thought of at the time by the Prof, or simply just didn't happen.

Eomer of the Rohirrim - Or maybe Thranduil secretly feared that Legolas would usurp his throne, and so sent him to his likely death.

Since the Elves were leaving, why would he have thought that?