The fact that Rachel and Kitty looked alike and no one mentioned it was rather dumb, but, as to the Maggie/Josette thing that stefan mentioned, this would have worked with Kitty too, she was the governess to the children of the man she married. She married him for his title and wealth, she was after Edward because she mistakenly thinks he has money too. This is certainly an abrupt change from the Josette that Barnabas loved, yet she is the reincarnation of Josette. Rachel was not! Rachel seemed to have the looks of Josette and was closer to her personality than Maggie or Kitty. It has been stated that Kitty was the only true reincarnation of Josette though.
As an interesting character Kitty tops Rachel. Too bad that they didn't have the Rachel played by someone else.
I also think, that Barnabas constantly falling in love with women who don't resemble Josette, weakens his supposed love for her. ie: Vicki and Roxanne. Although, when they first introduced Barnabas, he said that Maggie reminded him of Josette, not that she looked exactly like her, then when he failed to make her into Josette, he turned to Vicki to be the next Josette. The story wasn't completely fleshed out at this time.
When Barnabas first entered the old house he asked Josette why she hadn't protected him, after all he was a Collins, They must not have had the idea to make her his love interest yet.
Misa