Sorry for the triple post, but you know I love to find redheads. I can give you a list of suggestions and give physical descriptions of each one. I'll let you know which ones I think match the other sisters best, and I'm sure I can find several options. Abigail is played by Hayley Williams, so she has bright red hair (Hayley dyes her hair, but I don't know if Abigail is supposed to naturally be a redhead...and just dyes her hair to make it brighter, or has that hair naturally). She's a bit petite and rocker-ish.
Both twins are played by Karen Gillan, and have slightly different body types. Both are 5'5", but Vanessa is more athletic, lean and muscled. They're pale with longer red hair and such. Veronica is a bit curvier, but not big by any means. She still looks petite, but she has more of an hourglass figure, as she isn't as into sports as Vanessa is. She likes swimming casually though...and that keeps her healthy and never overweight.
The mother is played by Charisma Carpenter, who is a slightly tan and slender brunette. I think she has brown eyes. I'll have to check.
Andrew is played by George Clooney, so he's classically handsome with salt & pepper hair.
Richard is played by Henry Cavill, who Superman in the new movie. Another classically handsome man with a dimple on the chin and wavy brown hair.
Peter is played by Adam Brody who, while very good looking, could be seen as a bit smaller and could fit the nerdy stereotype better than the other two. He's still super hot, though. Also has dark brown curly-ish hair.