Harry and Isabella Potter & the Philosopher's Stone

The Evans and Potters are one of the most richest Pure bloods among the Wizarding World, but one prophecy changed it all. Harry and Isabella Potter are the twins who lived. Harry ended up with the Dursleys knowing nothing about him while Isabella grew up with Alastor "Mad-Eye" Moody and knowing that she was a powerful pureblood witch. What happens when they meet at Hogwarts for their first year?