She might have body issues herself but that makes her actions worse. Next time she starts looking you up and down or oddly nip it in the bud. Ask her then and there why she is looking at you like that? Or Is there something you want to tell me? Tell her it makes you feel really bad and hurts you. Tell her if you wanted any advice that you would ask some-one else for help.

She isn't being a friend. Friends do not do that.