Olga looked like her father, and a lot of people say she resembled her mother in some ways too; Tatiana has always known to look like her mother ("almost a perfect reincarnation," according to Ania V.) ; Maria was essentially a Romanov, and Anastasia is said to have taken after her mother's side, although the same cornflower-blue coloured eyes as her father. I actually think Anastasia looks a lot like her aunt Irene.