Read your cruise contract. Most have a one year statute of limitations with six month notice requirement. But again, READ YOUR PASSENGER TICKET.
I hope your wife is doing OK.
The answer to your question will depend on the fine print of your cruise ticket contract but with most major cruise lines: Carnival, Royal Caribbean, NCL, there is a 6 month notice requirement (which means you must give written notice within 6 months of the date of the incident), and a one year statute of limitations (which means any case must be filed within 1 year of the date of the incident.
Most importantly, this same fine print requires that any case be filed in Miami, Florida. This is a called a forum selection clause and they are enforceable. Feel free to contact me directly at mw@lipcon.com as the entirety of our legal practice is devoted to helping cruise ship passengers and crewmembers recovery for injuries sustained while at sea.