First topping

Usually the first topping is done above the 3rd or 4th leaf node (not including the cotyledon/ first set of round leaves) since you're growing in a micro grow I would suggest topping once the 3rd node had fully grown and start LST 5-7 days later with tying down the new growth shoots and promoting lateral growth to use your growth space more efficiently. I would also suggest filling up the pot with a bit more soil and to fertilize her, she seems to start developing some Nitrogen (N) deficiency, otherwise seems very healthy!! Good luck!! and happy growing :)