Sarah
Sarah will first She will most definitely say I love you first because she is very open about her feelings towards you, she will turn to you one night and say "I love you my little spider" which is her favourite pet name for you, you'll obviously Smile and tell her you love her too, and after that you'll just cuddle all night telling stories about each others life's
Winnie
winnie will not say it first, it will be up to you, you are way more lovey dovey then winnie, she will say it back but you have to grow a pair and say it too her, and when you do she will be taken back but after a few seconds she will respond. Winnie finds it hard to show her affection but she does it in her own special way so you know that she does