I wont give up till I find her

This book is about 2 girls.Their parents get split up.One of the girls are called called Lexy which is 6 and has moved in with her mum and her step-dad and has to leave her beloved sister which is called Chole and is four.However,once they become bigger Chole gets told that she has and older sister she goes out into that big world to find Lexy.Will she find her or will she not read on and lets see....