Yes, you can design and illustrate it as you desire.
Flowers, birds, synagogue anything.
Look up for some ideas on some web site for old ketubot.
ketubah = כתובה
A ketubah is a marriage contract. The ketubah is like a marriage license from the state, but it is made up for Jewish couples. It has elements of a prenup in it, and the rights and obligations of the man AND the wife.
Ketubot
Neither a relative of the groom nor bride can sign the ketubah - it has to be a Shabbat-observing non-related male.
No, the ketubah is signed in a private ceremony before the public ceremony. It is read out loud during the public ceremony though.
Call your rabbi and ask about how to get a replacement.
Ketubah
A ketubah is a sort of Jewish marriage contract, designed to protect the wife financially in the event of a divorce or her husband's passing. Custom ketubahs are available at a variety of places.
Ask the rabbi what to do.
It's the Jewish marriage contract.
There is the Ketubah which is signed by the husband and the wife at the wedding. The Ketubah is basically a Jewish declaration that you are husband and wife, and that you promise to be faithful, kind, etc., to each other. It is not a legal document. But if you are religious, under Jewish Law, they take it very seriously. There is actually a form of a court that is make up of rabbi to settle issues in the community, but I digress....
As I can see no reason to think either Susan Fontanarossa or Domenico Columbo were Jewish, so they would not have had to sign a Jewish prenuptial agreement (Ketubah)