Well, I don't mind the size of the images. You have to keep in mind that some images are smaller or larger than others so while some can handle a LOT of compression others will look really bad.
I found a program called PhotoELF that will compress batches of images. I'm sure there's others but in any case while trying it out the compression for the image I tried was awful, and by no means as good photoshops.
If you HAVE to have a ton of images for girls this may be one of your better options. (I tried 80% on one girl AWFUL quality)
I heard a program called Breezesys works wonders as batching.
It can be found below. I havent tried myself so I can't confirm. (Trial only allows you to compress 12 images at a time, which should be plenty for this game.)
http://www.breezesys.com/downloads.htmIf I run out of disk space because of WM, something is seriously wrong, and I think it would have more to do with my psychological state than the size of the image files. >;o)
The reason they're so large is so you can add your own girls. If you ever played Sim Brothel you'll see how small it is. However, with that game you can't add your own girls or really customize it at all. I think girls only have 3 images as well.
/Wall of text.