Hi Daisy11:
When liners are new, they can be stretched, but this is not the case after a year. If there are wrinkles or slack areas where your liner has relaxed, then you may have some material that you can use so that you could pull your liner back where it belongs. If your pool wall is steel, you should at least tape the exposed edges of the liner so that water does not get between the pool wall and the liner. Otherwise the pool wall may start to rust.