Evidence is the use of information to support a conclusion. A piece of information may support 0, 1 or many conclusions; it should only be referred to as evidence when supporting a conclusion, otherwise it is only information.
So: If I have two sources which both contain information about the birth-date of my great-grandmother, and I am trying to work out when she was born, then both pieces of information are evidence. I may weight one piece of evidence higher than another when deciding which birth-date is more reliable, but I will explain why I did so in a note:
"Cousin Charlie always said our grandmother Mavis celebrated her birthday on 1st April 1911, but her birth registration on 30th August 1911 by her father Alfred said she was born on 25th July 1911. Her father Alfred was recorded in the England and Wales census as being away from his family home on 2nd April 1911, and trade directories for the same period show him practicing his business as a photographer 200 miles away in July 2011 (where Mavis is recorded as born.) There is no obvious reason for Mavis's mother and siblings to celebrate the wrong birth-date, but the penalty for late registration of a birth may have caused Alfred to falsify the date and place when he registered it."
If there's a piece of information in your family record etc. that isn't relevant to a conclusion, then it's still information and not evidence. That doesn't mean you can ignore it if it doesn't fit with a conclusion you've reached; if it is relevant, it's evidence. However, your evidence might be my information if it isn't relevant to my interests.