The Linnhe Girl by J C Milne.
This book is 55 pages long.
 
Once upon a time there lived in Loch Linnhe, where Ben Nevis raises his snowy head, a water creature. She may still be there. If you look along the shore you might see her friend, the hermit crab, scuttling in the little waves, or spy the cave of The Otter King. You probably won’t see The Linnhe Girl. Her long hair looks just like the waterweed, floating on the waters of the loch. But here is her story, just the way old Grandmother Trout told it to me.