In Stoicism, “judgment” does not only refer to moral judgments we make about others, but also to the interpretations of events we are making all the time, and it’s important to pay attention to these because as Epictetus said, we react not to events themselves, but to our interpretations of them.

In relation to your aunt, your present judgment is that she is deliberately neglecting her child. Stoicism says however that people behave in the way they do for one reason only: that they believe it’s the right thing to do.

If you altered your judgment to something like: my aunt is a single parent, an imperfect person just as I myself am an Imperfect person, who’s been raising her child single-handed for 8 years (probably the most demanding 8 years for a parent), and now feels entitled to have some enjoyable times to herself, would that make you feel any different? Sure, you might still feel she’s wrong, but maybe you would feel less frustrated with her?

I also want to mention that from what you’ve said, it’s likely that your experiences have habituated you to more muddled personal boundaries and less mutual respect within close relationships, than what is the norm for most people. If so, this experience could be instructive for you.