Compatibility is a bit of a tricky subject in astrology, due to the wide range of theories about which planets and placements actually matter. When it comes to reading you and your parents, an astrologer will analyse your relationship with one parent and then the other (trust us, it's simpler that way). First, they'll lay your charts on top of each other, so that all of your respective planetary placements appear to be on one mega chart known as a "composite chart". This way, the astrologer can more easily compare where the sun is on your chart to where it happens to be on your mum's chart, for example. Then the reading will begin in earnest.