Sue Bentley 
Magic Kitten: A Summer Spell 

Flame is prince and heir to the Lion throne but he is not yet strong enough to stand up to the evil uncle who killed his parents and is trying to claim Flame”s throne for his own. Flame must hide in the human world as a kitten but can”t stay in any place for too long for fear of his uncle finding him. So Flame travels from family to family in various kitten guises using his, often chaotic, magic spells to help those who need it along the way…
Lisa isn”t happy that she has to stay with her aunt in the country for the summer – she”s going to be so lonely and bored. But then one morning she finds a tiny ginger kitten in her aunt”s barn and suddenly Lisa”s summer looks much brighter…