Fancy guppy lying on the bottom of the tank, will it die soon?

a fancy guppy (female) was nipped by tiger barbs last week but i have removed them & at first she seemed to be better, but now i can't be sure. her partner who was in a worst shape than her, is fine now, swimming around. but she's just laying at the bottom of the tank among the pebbles & seems to be leaning sideways. why? will she die soon? can i cure her? she hasn't been eating either.