Yes, ELABORATING is a Scrabble word!

Letter values in Scrabble US: E 1, L 1, A 1, B 3, O 1, R 1, A 1, T 1, I 1, N 1, G 2.

Is it a valid word?

ELABORATING is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
produce from basic elements or sources; change into a more developed product
make more complex, intricate, or richer
work out in detail

Also: flesh out, work out.