Sabrina Frank was cast as Vera in 'Eclipse', Rosalie's friend in her back story. Her part was eventually cut from the film. In an interview with Glamour (Germany) she talked about Rob and Kristen.
Rough translation of the part where she mentions by KstewRobFans :)
Glamour: Did you notice the Hype around that Robert Pattinson & CO.?
Sabrina: Yes, and how. It really is unbelievable that the fans will find all these locations. On my first day of shooting, we are driven into the middle of the woods, I would have never found this way - and when we got there, there were already dozens of fans waiting. I was completely shocked, but my driver said, the fans usually know already, which is rotated before it even know the driver. While it is all off and they do not come anywhere near the set, but for the fans is the greatest, when a car drove past in which they might sit Robert Pattinson!
Glamour: Did you meet Robert personally?
Sabrina: Yes, I sat with two times with him in the mask. That was altogether a very calm and really pleasant situation. I also met Kristen. I respect Robert and Kristen and the job they do and am very grateful that I got to know them.
Glamour: Did you feel Robert & Kristen were arrogant?
Sabrina: It is surprising that the actors who had more minor roles in "Eclipse", I met with a much greater arrogance, as Robert and Kristen. Some people did not even shake my hand or looked at me in the eyes. That was all very superficial. Kristen and Robert on the other hand looked at me very interested, shook my hand and listened as I spoke. I found them very enjoyable and authentic, very different than you expected.
Glamour: At that time, so the rumor bubbled to an affair of the two, you see something like this?
Sabrina: No. I only saw them together once and I think they are way too professional to kiss and cuddle on set
Glamour: You were four days immersed in "Eclipse", what were your highlights?
Sabrina: Meeting Robert and Kristen. And to see how human the two really are. I would love to do them any good because I feel so sorry. You need to hide all the time, because at the fences hang the teens. They don't have a single minute for themselves. That one still remains is so normal in my eyes an insane performance. Also, I was taken seriously as an actress, I was allowed to speak in the trailer by director David Slade, like any other actor too - and with him about my role. It was great.
Read the full interview at the source