A good place to learn is Jack Keller's wine-making site. He has a lot of info about "country wines," or wine made from anything other than grapes. Here are his black current recipes
. Your gf should not just follow these recipes though. First read more about the process (also on Keller's site). Then she may need to adjust the juice or "must" (wine equivalent of wort) before starting fermentation. IE, specific gravity by adding sugar, or acid or other things. Winemaking is similar in some respects to beer making, but pretty different in others, so your beer experience may (or may not) apply.
When I experiment with a new juice or fruit, I sometimes make a few variations with one gallon jugs. Wine takes a lot longer to develop than beer, but you should be able to see early on if one of the jugs shows promise. There are a lot of other forums and info about wine making, but the Keller site is a good starting point. Good luck.