Co-drivers in the same heat is pretty standard. It will not be a problem. You will not be able to ride with your co-driver, but can coach as much as you want between runs.
Clarification - the rules state you cannot do ride alongs prior to or during your heat if you want season points for that race. The ODs can grant an exception...or if you don't care about the points, feel free to do whatever you want. We actively encourage new people to ride along with more experienced folks and often ask experienced people to ride with novices who are having problems with the course.