Translation:What are they learning?
tI did a little research and found this website https://french.kwiziq.com/revision/grammar/forming-questions-by-inverting-in-the-present-tense-il-elle-on-forms which tend to end in a vowel (like "aime", "va", and "mange") and that verbs ending in "d" (like apprend) don't because the d gets pronounced when followed by a vowel. So the correct sentence should be qu'apprend-elle. We mis-heard the sentence. We learned a rule about adding a "t" to "il" and "elle" and overgeneralized it, just like a kid learning English might say something like "I go-ed to the park", having learned to add "ed" to make a verb past tense. Sorry if this is too much information!