Roslyn, along with her sisters, was a product of a Cardassian project to create human agents. By hand, Dr. Alan Murrow created a series of human augments that are stronger, smarter, and would be able to integrate into human society. Because he was afraid of his creations turning on him, Dr. Murrow attempted to detach himself from their upbringing (USS Baldwin: "Drift off to Dream", "Departure"). She was only known as "Number Six" until she managed to leave Cardassian space and join Starfleet. Roslyn chose her name because it meant "beautiful rose," a name Dr. Murrow eventually agreed was fitting. (USS Baldwin: "The Find")
"Progress comes at a price, but the time will always come that the price is too high for some, while we look out to that next star; we sometimes forget those that we leave behind. This Federation was not formed on the principles of war, but on peace and exploration."