Gothel makes a cameo appearance in Rapunzel's paintings recounting the events that led to her return as a princess; this is seen during the film's prologue.
Gothel is also alluded a few times; when King Frederic and Queen Arianna discuss why he's so overprotective with Rapunzel, he mentally flashes back to the night Gothel broke into the castle and kidnapped Rapunzel.
During the climax, the antagonistic Lady Caine warns Rapunzel that, "she has no idea who's she's dealing with", to which Rapunzel retorts, "Believe me, I've dealt with much worse."
In the episode "What the Hair?!", Gothel appears in a nightmare had by Rapunzel. After sadistically bragging about her supposed return, Gothel summons the thorn-like rocks that appeared on the night Rapunzel's hair mysteriously returned.
Gothel takes notice of the hair and suggests that she and Rapunzel return to the tower where the latter will be "safe". Rapunzel abruptly wakes from the nightmare, though it prompts her to learn more about her revived hair.