My wife started hunting about 8 years ago when we moved to Colorado. On our first trip to Nebraska for whitetail, she shot a 5x5 on the first day. That buck was bigger than anything I had ever taken, so I think that helped hook her.
One big difference I have seen with our relationship versus some others I have seen is that she's not afraid to go by herself / without me. She doesn't want me to guide her. If I held her hand through every step like I see in lots of YouTube videos (I picked your unit, Scouted the area, Found you a buck, carried your gun, set up your rest, shoot when I tell you), I think she would slap me and send me back to the truck/camp until it was time for a pack out. Finding the right balance of being helpful vs being overbearing is something I am still working on. It is especially difficult for me when I've done research on an area and did not like it, but she wants to hunt it.
Pros:
Less time away from the wife / more time with the wife.
Being able to share the details of the hunt with an interested response rather than the "uh-huh" response.
Twice as many chances to experience a cool draw hunt.
Can extend your hunting season. A hunt isn't always about pulling the trigger. Colorado has very short seasons, so a great way to be in the field is as spotter/packer.
Understanding of why we're buying the gear we buy. After her first late rifle elk hunt, she didn't question the $$ dropped on a top level spotter.
Vacation time isn't all "trips to the beach" or whatever ( though we still do some of that stuff because that can be fun, too ).
Cons
We have to buy two of everything. That can be good, because there might be a backup, but its still twice as much $$.
We don't always agree on which hunts to do, and often intentionally get different tags, but sometimes tag dates overlap and it can be frustrating when I would prefer to be focusing on a different species.
Competitive nature can cause some strife.
You can run into the same issues with any hunting partner, but the consequences of not matching are worse: physical limitations, temperature tolerance, drive/ambition, hunting style. Don't force it.