To see your sister in your dream, symbolizes some aspect of your relationship with her, whether it one of sibling rivalry, caring, protectiveness, etc. Your sister may draw attention to your family role and sense of belonging. It may also serve to remind you that someone in your waking life has characteristics similar to your sister. Alternatively, your sister may be a metaphor and actually refer to a nun. In this case, she may represent spiritual issues. If you do not have a sister and dream that you have one, then it signifies some qualities that you need to activate or acknowledge within your own self. Pay attention to the actions and behavior of your dream sister.
The meaning varies according to context and sex of the dreamer. For a man, it signifies emotional security, but for a woman, it portends domestic disagreements. An objective dream of sibling unity between sisters is an indication of emotional stability.