If you look at my avatar, which is a full 100x100 pixels, it's a JPEG file and is only 3.5KB in size.
It doesn't have to be a large file to be a decent 100x100 pixel picture. You're not really going to get that much better an avatar by keeping it 60KB.
The JPEG image file format has the ability to use compression. The more compressed it is, the less sharp the picture will be. But if the size is only 100x100 pixels anyway, you'll still get a very good picture with a small file.
There is a free program that you can use to edit your photo to change the size (width and height) and file size. It's called IrfanView
. Or there are other programs that can do the same thing.
If you need help with reducing the size of your image file, you could email it to me and I could resize it for you. Let me know...