My sister and her husband will be celebrating their 4th wedding anniversary next month. My brother in law pleaded me to help him find the gift for my sister. And so I scouted the net for 4th anniversary gifts for her and I found out that the theme for 4th wedding anniversaries is something to do with flowers, fruits, linen or silk. I suggested to my brother in law silk pajamas. Anyway, I wish them more years of blissful marriage.