If you are really into photography I would recomment the "semiprofessional" lines of cameras, i.e. Dx00 line for Nikon, or the 70d/80d line for Canon. Thats because if you learn to use the controls, you can work fast with these cameras (lower cameras will often require lots of menu surfing).
And at least Nikon outright intentionally cripples the lower lines of cameras, such as not supporting HSS (the ability to use flash units in bright daylight with shutter speeds beyond flash sync, nothing thats overly complicated).
So after some more research I'm wondering if I made the right choice going with Canon.
The differences are rather minor.
Out of the top of my head, guaranteed to be incomplete:
Canon:
+ More speciality lenses (but Nikon also has some gems) like a fisheye zoom, or a magnifier lens
+ All lenses are autofocus (with the exception of a few speciality lenses) and mount on all cameras with full functionality.
+ Better ergonomics, namely better one hand operation (the only Nikon DSLRs that work well this way is the D5x00 line)
+ Dual pixel technology: fast autofocus in lifeview
+ Video: though Nikon added it first, Canon is usually seen in the advantage
+ Very high quality production in Japan and Taiwan
- Two class lens system that gives the "good", expensive L-lenses only to the professional; for example the 50/1.8 is actually lesser in image quality than the 50/1.2 because the later is an L-lens. This isnt the case with Nikon, because Nikon lenses are as good as possible no matter what, thus the 50/1.8 is actually bit better/sharper than the 50/1.4.
- EF-S lenses cant be used on full frame cameras.
Nikon:
+ All in all I think/believe/am prejudiced to Nikon > Canon with lenses when it comes to image quality
+ Compatible lenses since the first DSLRs (but lenses before 1977 need to be converted and many new lens/old camera combinations will not offer full features; the most recent incompability is E lenses which wont allow to change aperture on any Nikon film camera, or on older digital Nikon DSLRs), while Canon only dates back to 1987
+ High quality but affordable lenses in a huge used market
+ High quality Sony sensors, while Canon insist to use their own sensors
+ Probably best flash system of them all
+ Overall a tendency towards lower prices (but see disadvantages)
+ Overall more feature rich cameras (IS there even a Canon with two card slots of the same type ?)
- Known to introduce slight green tint for skin colors (can be fixed in post, mostly just a bit annoying)
- Illogical "reverse" way to mount the lenses (can drive you crazy in the beginning)
- Non-coated monitors might be hard to read in daylight
- Poor autofocus performance in lifeview
- Slow focus point selection in lifeview
- Cheap Nikon lenses (and some more expensive ones) are known for poor autofocus performance (in comparison to Canon)
- A lot of cheap chinese labor and as a result sometimes quality problems for example with the D600 and the D750
There is also a lot of advantages these two companies have over all competition, such as being leader of autofocus performance, having a large used market, having a large market of other companies like Zeiss, Tamron etc which make lenses etc for these cameras.
I thought about just getting a Nikon for me and letting her keep her Canon.
Depending upon your goals that might actually be perfectly possible. Quite frankly those two cheap kit lenses are nothing you will miss if you get higher quality lenses. Especially if you would get full frame, because you cannot even mount EF-S lenses on a full frame Canon DSLR anyway. You COULD mount the EF lenses on the smaller camera, though.