Cotton is the tradition for your secondary anniversary! It represents threads being interwoven, like how your lives have become. You are now interconnected, and move with each other. Like fabrics woven from cotton, you become flexible and move and flow with each other as time goes on.
These days, cotton is so everyday, she may be less impressed unless you’ve added a special touch to that cotton gift. China is the modern second anniversary gift. It represents the beautiful life you have built together, but it is still delicate, and fragile and though it is to be enjoyed, it must be handled with care.