If she is divorced and Catholic, she could obtain an annulment, probably easily in Florida, allowing her to remarry. If she is Catholic and they succeed in killing Terri, it doesn't sound like they could marry in the Catholic church, unless some canon lawyer found a way around the restriction posted above.
I tried to find the thread where we were talking about that on the regular news section and can't come up with it. I thought someone posted Jodi was Catholic and wanted a Catholic wedding. I haven't found anything substantive to support that statement. If neither wants a catholic wedding, they could easily find someone non-Catholic to marry them.