Are Peach and Daisy sisters

No. Princess Peach is best friends with Princess Daisy, they have been since they were babies. Daisy rules another kingdom, which is not so confusing. The confusing thing is that she live is the Mushroom Kingdom, like Peach. She wants to be near her friends. They are not even related, just friends. Some of the games mention that she has a father (duh!), but they never mention that she has a sister. Also, the guides for the sport games say that there is a friendly rivalry, that they are FRIENDS. Daisy and Peach are definetly not sisters