Goddesses of abstracts like nature, creativity or the hunt tend to get angry if you mess up any of their property - territories, animals or plants sacred to them, things like that - or if you fail to honour them in the manner to which they're accustomed, or if you insult them or their children or parents.
Expect the punishment to be quick, obvious and in some way appropriate to whatever she considers you did wrong.
I can't make any specific guesses about Sebastian's Lady. I don't know anything about her.