Just need to get through these next few months and hope it doesn't get messy, any advice on living in the same house and co parenting while in the divorce process would be very much appreciated?
MF, my divorce finalized about 6 weeks ago. We were separated in the same house from January last year until September. Kids all adults, son in the house for the summer. So not the same as your situation but not totally different.
Don't take the bait. If she is trying to get you upset, just walk away. Even if she isn't trying to do it, if she does or says something which gets you emotionally off balance or angry, just leave the house. I took the dog for many long long walks!
Realize that even in an amicable divorce there are going to be conflicts. Have your lines in the sand (but don't tell her what they are in advance), and stick to them. Use other things as give-aways. If she wants the couch and you don't have a big emotional attachment to it, let her have it but use that as collateral against something you want. Don't fight over everything, but if she is picking you to pieces on little item at a time, you should hold your ground. Basically, don't let her walk all over you. Get what you want and need.
Expect surprises. For me there were a couple of items which were kind of nuclear fire. One I knew about, the other surprised me when she brought it up. You may have to walk away and come back some other time to discuss it. Or, you might decide to hold your ground on it right there. The point is, control your anger. Expect to be surprised at getting angry about something, and resolve today to keep it calm when that happens. You're going to be prickly about custody and about the house, but something for sure is going to come up and surprise you. Maybe it is the garden tools, maybe it is a painting a friend gave you. But it will happen.
Oh, talk to a lawyer asap. Even if you are going to do this mediated without lawyers arguing, you need to get a good consultation so you know how things work and what your rights are. You may need a lawyer to do some documents to be sure they are done properly. Even if you agree not to use lawyers to argue, it is smart to use a lawyer when the documents exceed your expertise.