I got this little jacket one size larger because I wanted my girl to be able to wear her Fitwarm jammies underneath, for winter potty trips outside. It is the perfect size for this. It's also very easy to put on her, and really warm. It's brightly coloured so she is more visible in the dark, stylish, and reversible, so it is very versatile. I absolutely love this little jacket. It's our favourite out of her collection.