Can a document not exhibited be read in evidence?

My 125 CRPC maintenance case has reached its conclusion, and I intended to appeal this decision in the High Court, but one of my crucial documents was not exhibited in family court. Will the high court now accept that same document—which was not exhibited—as proof? If not, how can I use that document, and what are my other options moving forward?(The document I am referring to is a generic income statement for my husband that I obtained from online RTI).