She is searching for light so if you put her in a bigger pot she will continue to stretch until she finds enough light.
Give her e bit more light and the stretching stops and you got the feeling she is gonna fall over place a stick for support.
roots are very fragile at this stage so it’s better to let her fill the cup so you minimize the risk for severe root damage
Hi, make sure you have a little breeze on it, to strengthen the stalk, as well.
Covering more stalk, without it being stiff and a more fibrous, may start to rot the stem.