The UV packing is not that good on the dress, also, you probably want to have the head on a separate mesh so that you can give it the right amount of UV space there’s also to take in consideration that most of the body is covered by the dress, you could remove those polygons that are covered anyway and gain a lot of UV space for other parts.
There is a nice tool on Blender, it’s called TexTools.
You can use it to easily show a checkermap on your model, match the texel density of the various meshes and other cool stuff.