Protecting Her Son?

In class the other day, we watched a particular production of Hamlet. The version was modernized; it took place in New York City with Denmark as a corporation instead of a country. When we watched the ending scene (the one where everyone dies), I was confused. In this particular version, it appeared that Gertrude knew that the cup of wine had been poisoned. Whenever Claudius tried to hand the cup to Hamlet, Gertrude made excuses or pushed the cup away. She seemed to be trying to protect Hamlet from Claudius' plot. And when Gertrude took a drink from the poisoned cup, it didn't seem to be an accident; it appeared that Gertrude knew what she was doing. In a sense, Gertrude was sacrificing herself for her son. However, this sacrifice would be in vain.

I turned to the last scene again to see if I had missed something. Maybe Gertrude had known what Claudius had done, maybe Gertrude was trying to protect Hamlet. However, the text didn't seem to indicate so either:

Claudius: Gertrude, do not drink.
Gertrude: I will, my lord, I pray you pardon me.
She drinks [then offers the cup to HAMLET] (5.2.233-234)

The fact that Gertrude offers the cup to Hamlet after she drinks contradicts the idea that she knew the cup was poisoned, or that she was trying to protect her son. After all, why would she offer the poisoned drink to her son if she was trying to protect him? Even though the production that we watched did not accurately follow this particular moment in the plot, the production was still really interesting. I wonder what caused the producers to make the changes that they did (portraying Gertrude as a mother who dies trying to protect her son). Perhaps they were trying to show Gertrude in a different light. Hamlet, throughout the entire production, accuses his mother of committing horrible deeds. Maybe, when portraying Gertrude differently, the producers were trying to give her a fair portrayal. Perhaps they felt that Hamlet was unfair to his mother when he called her a villain, and many other names. Maybe they felt they were righting the wrong. Regardless of their reasons, it was definitely a unique choice. I wish we had the time to watch the entire production so I could have seen whether this stylistic choice was carried out throughout the entire production, or whether it happened only at the end.