We do not always carry matching weapons, but I figure it is a plus if my primary or secondary weapon is something that is familiar to her. Our best common weapon is the S&W mid-sized revolver. Next best is the S&W J-Frame, a better fit for her, than for me. She is less familiar with my Ruger revolvers, but can make them work.
Our common defensive shotgun platform is the Remington 870. We have a cumulative total of three, and I have been eyeing a pre-owned Wingmaster, at an LGS. (I consider the Benelli M2 to be my go-to long gun, but she probably could not run it.)
We each had Kahr K9 pistols, in the Nineties. This worked until my sole supplier of 9BPLE ammo changed ammunition brands. Her K9 fed/feeds anything, whereas mine did not. I sold or traded my K9, somewhere along the way, since then.
She bought herself a reliable Walther PP .380, which she loves. I have bought, and then sold, several PPK and PPK/s pistols, also .380, in an attempt to make that platform work for me.
She does not like Glocks, but when I want to carry a Glock, as primary, that is what I carry.
We each have lever-action rifles, and each of us could run the other’s, except that my box-mag-fed .308 BLRs might confuse her, at reloading time.