Yes, COWBERRY is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, W 4, B 3, E 1, R 1, R 1, Y 4.

Is it a valid word?

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

low evergreen shrub of high north temperate regions of Europe and Asia and America bearing red edible berries
tart red berries similar to American cranberries but smaller

Also: mountain cranberry, vaccinium vitis-idaea, lowbush cranberry.

Not playable in Scrabble US: LINGENBERRY, FOXBERRY.