At the beginning, there is a scene at the embassy of the USSR. The brass plate at the entrance to the embassy reads, "Union of the Soviet Socialist Republic," although the correct form is "Union of Soviet Socialist Republics."
"Regimirov" is not a correct last name for a Russian woman. Most Russian family names originated from patronymics, that is, that father's name usually formed by adding the adjective suffix -ova or -eva for a female. (Peter or Petrov, Ilya or Ilyov for sons, Petrova or Ilyova for daughters). Contemporary patronymics have a -na for female names. For instance, if a single woman's father's last name was Ivanov or Petrov, her last name would be Ivanova or Petrova. So technically, Katrina's last name should have been Regimirova.