With some shallow understanding on how those models work, this looks much more like usual hallucination likely due to sparse data around "Tabitha" and "Cherry"

With some shallow understanding on how those models work, this looks much more like usual hallucination likely due to sparse data around "Tabitha" and "Cherry" which makes a single training data much more representative. If you try some common names like "Emily" or "Sarah", it will just do the job. If you're trying to make the case that it's cheating because it is already in the training set, then you probably should come up with different questions. This is machine learning 101.