Brother & sister don't always make successful pairing in figure skating. It may be because they can't appear romantic, and it limits their expression somewhat. Still, there have been some good partnerships. Interestingly none of these are Russian.
Peter & Kitty Carruther - Olympic silver (pairs)
Otto & Maria Jelinek - not sure if they were world champions (pairs)
Paul & Isabel Duschenay (sp?)- Olympic silver (ice dance)
Maya & Alex Shibutani - world bronze (ice dance), and hopefully more to come
John & Sinead Kerr - not sure of their highest finish (4th in world?)- ice dance
Steve & Danielle Hartsell- US nationals champions
Beck & Beck (German ice dance team)- not sure of their highest finish
Tiffany & Johnny Stiegler- Not sure if they even medaled at the senior level at the US nationals
I am sure there are a lot more.