In an interview with The Express, Karen Gillan revealed how she felt "privileged" to play Amy Pond.
“I feel privileged as an actor, and to have one of the big plot lines. I am very excited about Part 2. I’ve seen a lot of it, though I can tell you it’s a very different experience from seeing a rough cut, without all the colours, grading or the special effects. Relationships are developed in so many ways. We’ve got some great new monsters too.”
She also revealed she didn't know River's true idententity until she got the script for Let's Kill Hitler!
“I didn’t know. I only found out when we did the read-through. I just couldn’t believe it. I was so excited that it had panned out like that and I thought it was such a good pay-off. I had always wondered, ‘Who is this woman?’ when I saw her in a David Tennant episode.”

“We had decided from the start that there was never any jealousy between Amy and River, which has happened before with assistants. We didn’t want there to be any of that.

“They have always respected each other. Alex knew about the plot revelation, but I didn’t. Steven Moffat likes us to have secrets from each other.”