I don't really get how people are calling Sylvia a 'granny' name, and yet are happy to give their children names such as Florence, Elsie, Wilfred, Arthur etc. - far more 'old people' names if you ask me and unattractive.
Sylvia, OK it was popular pre-war, but it is a classic, features in poetry etc. Then there's Sylvia Plath. It's lovely, as are Silvia and Sylvie. French people think of Sylvie as middle-aged though apparently.