I know there is a lot of discussion on Mackenzie in other treads, but I thought I would start by giving my thoughts here...
When I saw the pictures of her, my first reaction was "She has amazing eyes, just like Edwards!" (the Edward in my head, that is) And then I realized that this is not possible, because she has green eyes (and obviously isn't a vampire

). So I was completly confused as to why she reminded me so much of Edward. Until I remembered that he had green eyes before he was changed and Bella wished that her baby would have Edwards green eyes! I thought it was so sweet

! (swear it happend that way. thought it was wierd to

) But Renesmee had brown eyes so she will probably wear lenses.
I haven't seen Mackenzie in anything before, but I saw an interview with her on youtube and she seems really nice and outgoing. I'm sure she will do a good job. I was worried about how they are going to portray Renesmee, but seeing her beeing cast took a lot of that worry away even though she is nine years old. I am curious about the CG they are going to use though.