So what I ended up doing was agreeing 20% of the intellectual copyright, I own the master recordings but will give her 80% of the mechanical. She's paying for somethings (session players, distribution costs but I will be doing all of the "work").
I am now in manager role with her so it's in my interest to make it work I guess.
A band I know (killamonjambo) started in a similar position and the manager (Andy) paid for everything, (van, gear and built a studio) he takes 20% gross and it's worked out. The band have gone from teenage garage band to 2-3 European tours a year. And they are all happy with the arrangement.
Hope that helps.