Why can't she just play in her BDUs if she has them? I played in BDUs for years and they were super comfy. If she wants pants, I just go by the waist and any pants I've bought have been fine, even with hips. If she's on the top end of the waist I would buy the next size up, they're almost all adjustable around the waist.
I've never used a neck protector, don't think I would like them personally, but she could always tie a scarf (or something scarflike) around her neck. I don't know what your wife does, but I work in a law firm and only one time have I had visible bruising on my neck, and it was obviously from a paintball. Everyone just looks at me like I'm crazy to even do it.
As for chest protection, fold up a towel in a sports bra for a tight fit. I don't like tight clothes and prefer nice, loose fitting clothes to play in so I wouldn't be too concerned about making alterations on a jersey.
I use the JT Flex for a mask and it fits great. One of the few masks out there that gets small enough for my head and doesn't move around a lot.
You can rent it at most fields, check the one you're going to before you invest money in it. They may not like it and then you're out that money.
As a girl who plays, I don't wear anything other than a sporta bra and if they don't want to spend the money on a chest protector, just wear a sport bra and fold up like a hand towel and put it inside the bra. Then if they wear a sweatshirt or something that should be plenty of padding.
Honu and I talked about heading down Thursday night to set up camp. If we do that, one of us can probably pick him up at the train station in Joliet if he can get there. Depending how far it is from CPX he can give us a call when he leaves O'Hare and we'll meet him there.