Yes, SQUABS is a Scrabble word!

Letter values in Scrabble US: S 1, Q 10, U 1, A 1, B 3, S 1.

Is it a valid word?

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

flesh of a pigeon suitable for roasting or braising; flesh of a dove (young squab) may be broiled
a soft padded sofa
an unfledged pigeon