I want to take my parents to Hawaii this September and initially had planned for a week in Maui. However, my dad wants to visit a second island. We thought about a few days in Oahu. Do you think this is a good idea since we only have seven days total to split between two islands? I have done more research on Maui so don't really know much about Oahu, but my parents love going to the beach so gorgeous beaches will be the main criteria.