I'm talking about two characters. Victoria Tamerlane (not sure of the spelling) was introduced in 1984 during the Barbados story. She was Brandon's daughter by Sharina and, thus, the sister of Alan, Alex, and Amanda. She's seen here in this clip:
The late Kim Hamilton played Victoria.
http://variety.com/2013/film/people-news/actress-kim-hamilton-dies-at-81-1200803013/
Vicky Brandon was introduced in 1998 and was Michael Burke's research assistant during the cloning storyline. She was first played by Karen Williams. Victoria Platt then took over the role. Vicky originally had an accent that was dropped after a few months. Vicky was revealed to be Victoria Tamerlane's daughter, making her the niece of Alan, Alex, and Amanda. During Vicky's story, it was established that her mother Victoria was deceased.
Hope this helps!