For a special gift for the Bride why not buy a nice small notebook before the Hen.
Ask the Brides older relations - like her aunts, older cousins, grannies and her mother to write her a short message in the notebook with some advice for married life.
Get as many as you can and give it to the Bride at the Henparty. Maybe wrap it in tissue paper and put it in a little box.
A very special gift from very special people in her life. And years of advice to draw from!