First of all, good for you for having a positive self-image, even when your mother is critical! Her views on weight may go back to her own personal negative experiences with body image. If talking to her directly doesn’t work, can you ask someone else to talk to her – someone who she respects? Maybe she equates “super skinny” with “magnet for marriage proposals”. It may take one of her peers to help her change her thinking. Meanwhile, don’t let her obsessive thinking affect your healthy thinking. How she perceives you should not affect your own self-perception. Try to imagine a force-field around you where you don’t let in her negative attitude. Feeling happy with yourself is a key to a happy marriage……when you’re ready for it.