AerandirAgarwaen, princess_stomper, GilgaladhThanks for replies guys, i still don't really get it if i'm honest! Could i say, play single player, complete it and have like lets say great weapons/gold whatever on the girl character and then transfer that over to my co-op gameplay? so could be like level one, my girlfriend has starting gear but i still have my epic stuff from my single player save? does that make sense?
Also i found a thread on another site and somebody explained the "Adventure +" feature (NG+) and this is what was explained:
Spoiler Starting a New Game+ erases all previous progress and restarts your characters in chapter 1 with a red runed epic 37 dmg fast crystal sword and a red glowing epic 27 dmg fast crystal bow, as well as 32 skill crystals which is enough to max out all skills and spells on the first tier. Also unlocks Old School difficulty, poor E'lara will get 1 shot by dual wielding enemies if she's hit when you are controlling her and fail to dodge or block it.
The original 212 dmg fast blue crystal sword and 151 dmg fast crystal bow are also found in chp 6 if you've collected all 3 keys from crypts in Chp 1 2 and 4.
*Also, gold count transfers over, but talents, dragon tear, death stone bodies, and freeing prisoner counts are reset
*What seems to be the biggest change is the addition of campaign tweaks: under special features > extras a list becomes available that lets you enable certain things like unlimited or regenerating arrows 10x battle charge duration 1 shot kills stone skin health and mana regen big/small head modes and using special skins for your characters.
Was good info so figured i'd pass this along

If anyone could help with my question above that'd be brilliant!
Thanks