A person dressed in white and black winter clothing leaps a narrow, water-filled ditch from one frost-covered field to another, where a female dressed in black coat and pants awaits.
The female awaiting the man leaping is his sister.
A person can be male or female so a person who leaps might not be a man, and a female who awaits might not be his sister.
A person and a female don't imply that they are a man and his sister..
Just because the female is awaiting the person on the other side of the narrow, water-filled ditch, does not mean she is his sister.