These all work for me except (b). " She is not in jail. She is not a slave.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Vincent TeoCan I say,Yes. (b) implies some prior context in order to use the defiinite article. You could avoid this problem by saying "her free time."
(a) She is painting during free time.
(b) She is painting during the free time.