I did this lots of times for my sisters.
Think kid toys: play doh, silly putty, bubble solution. I sent this kit to my sister once that was a water gun wiht a bottle of bubble solution the idea was that you blew bubbles and shot them with water to pop them. That was a hit.
I mainly thought of things to do to take a break from studying. Some treats are good, trail mix or some kind of cookie she likes.
“When one door of happiness closes, another opens; but often we look so long at the closed
door that we do not see the one which has been opened for us.”
Helen Keller (1880–1968)