My wife is up & down with it. I never had fish before she got me into them, she kept a 10gal in college for a bit. She didn't really know anything about keeping fish though, she just had pretty good luck with minimal maintenance on that 10gal, and it was only around for a few semesters.
So she got me into it, we had a huge disaster (failure) on the 20gal we set up, and I took off from there. The fish genocide spurred me to do better research the second time around and get things right. And its around that time that she started getting annoyed with me. I started learning quite a bit about it and she wasn't really keeping up. I think she just wanted it to be as easy as it was for her in college, so when I started dealing with all the regular maintenance stuff like water changes, dechlorinator, test kits...just basic stuff; and then things like what fish we can ACTUALLY keep in the tank we have etc etc. She didn't really want to deal with all that.
Now we have a 65 a 55 & a 20g, shes 'banned' me from getting any more tanks until we get a house (and she's starting to hold babies against me too

) but I'm ok with that so I'm not arguing it. She does get to her wits end sometimes when I start talking about what I want to do with the filtration & the lights & all that jazz, but for the most part she listens & she's getting a lot better about trying to learn.
At this point I think she's just letting me rock these 3 tanks however I see fit but putting a clamp on the budget when I get to going overboard. Once we can afford it though I'm either getting a larger tank for some of my FW and re-purposing the 65 or 55 for SW, or just getting a new tank for SW. I'm hoping to let her handle that since its what she REALLY wants out of all this fish business. We'll see how it goes.
So overall, she's ok with it, she just gets REALLY annoyed sometimes with how deep I'll dig into a rabbit hole...that goes for all of my hobbies & interests though, so its no surprise.