There is an imaginary 24-hour line around the base hand to indicate a time period of the day/night.
Gloss: /\LAST NIGHT/\ IX1 START COOK++ ALL-NIGHT STILL/\.
English equivalent: She has been cooking since last night.
Start with the information of time. /\ symbol for raised eyebrows. The pronoun is non-gender in ASL.
The verb COOK is inflect to agree with time tense. Likewise for ALL-NIGHT (the movement and mouth morpheme).