similar?

My uncle, Hans, and my dad. They are twins.
But I have always been able to tell who's who.

My uncle's wife Eva, that we celebrated on her 50th b-day, and my mother. Many years ago they bought the same blouse in Florida and they both picked out it for the party. What are the odds?

My sister Ingrid and I. We are not really similar,
maybe in only a few ways.
But we are sisters.