"nuHmeyna' bIH nuHmeyDaj'e'."
Translation:Her weapons are real weapons.
-na' means that the speaker is absolutely certain that the noun it's attached to is the correct noun.
If you've got a DevwI' (leader), and you want to make the point that there can be no doubt that the person being described is accurately described with the word DevwI', you can use -na': DevwI'na' true leader, definitely unquestioned leader. This person is so leaderly, it's obvious that they really are a leader.
The same goes here. If you've got nuHmey weapons, and you want to make the point that there is no question at all that these things are definitely nuHmey, you can say nuHmeyna' true weapons, definitely unquestioned weapons. These things are so obviously weapons that no one could possibly think they're not weapons.
Exactly how you translate that into English can vary. True leader, real weapons, unquestioned pudding (wIlpuqna'). There is no single word that translates from -na'. Your translation of definitely weapons is fine. You didn't say whether your answer was accepted. If it wasn't, that may just be because the person who wrote this sentence didn't think of every possible translation of it.