Fully awake:
— So excited she was wide-awake all night.

synonym: unsleeping.

Roget 498: intelligent [Applied to persons], quick of apprehension, keen, acute, alive, brainy, awake, bright, quick, sharp; quick witted, keen witted, clear witted, sharp-eyed, sharp sighted, sharp witted; wide-awake; canny, shrewd, astute; clear-headed; farsighted etc. 510; discerning, perspicacious, penetrating, piercing; argute^†; quick-witted, nimble-witted, needle-witted; sharp as a needle, sharp as a tack; alive to etc. (cognizant) 490; clever etc. (apt) 698; arch etc. (cunning) 702; pas si bete [Fr.]; acute etc. 682.    wise, sage, sapient, sagacious, reasonable, rational, sound, in one's right mind, sensible, abnormis sapiens [Lat.], judicious, strong-minded.    unprejudiced, unbiased, unbigoted^†, unprepossessed^†; undazzled^†, unperplexed^†; unwarped judgment^†, impartial, equitable, fair.    cool; cool-headed, long-headed, hardheaded, strong-headed; long-sighted, calculating, thoughtful, reflecting; solid, deep, profound.    oracular; heaven-directed, heaven-born.    prudent etc. (cautious) 864; sober, stand, solid; considerate, politic, wise in one's generation; watchful etc. 459; provident etc. (prepared) 673; in advance of one' age; wise as a serpent, wise as Solomon, wise as Solon.    [Applied to actions] wise, sensible, reasonable, judicious; well-thought-out, well-planned, well-judged, well-advised; prudent, politic; expedient etc. 646.    ... show more

Fully alert and watchful.

synonym: heads-up.