My wife is not a hobbyist. She is very conscientious with money though and I'm lucky (?) enough to have a whole failed fish store worth of aquariums, filters, lighting and so forth. And I tend to trade fish, plants and shrimp to support my hobby, so not a lot of money is spent. I do make some purchases of course but try to sell something to fund them when I can. So no arguments over the spending part; time and space are bigger issues. Our home is just under 1,500 sq ft and I have 5 aquariums (and a pond) here at the moment and another 4 at work. And naturally I want more.
I suppose having aquariums when you met would have made a difference. When we started dating, I had a lot of fish and breeding projects (as well as a lot of reptiles) and the hobbies did take up a lot of my time. She knew what she was getting into, and in our case it's gotten "better." As I get more out of fish and into shrimp, the biggest change has been how much less time the aquariums take. I water change less, feed and fertilize less, there aren't jars of brine shrimp all over and I now probably put fewer than 3 hours a week into them, not counting just observing or rescaping for fun.
She likes the shrimp well enough and has a betta of her own in a 40 gallon tank. The betta was left at the door of my store when I came to open one morning and she wanted to keep him. She didn't know if it was a male or female (it's a male) so named it Carold which amuses me to no end. She loves seeing baby shrimp appear in our tanks, and to that end I've tried to encourage her to set up a tank that I'll maintain for her. I have a 10 gallon Dennerle shrimp tank still in the box for her to set up at some point and she can pick any plants from my other tanks and stock it with whatever shrimp she chooses -as long as it isn't stock from my current tanks. I'm hoping it's some sort of Taiwan bee, but will be happy as long as it isn't Neos since I've bought Aqua Soil. I've mentioned setting this tank up many times and the question is always "where?". If I were a single guy, I'd put it right beside the other one in my office but her sense of decor is more practical than that. So not sure when it will ever be filled, but it will be a big step in the right direction to give her creative control over one. I have no illusions that she will ever become an aquarium addict but if she can just have some pride in a pretty tank that she set up herself I think it would help her understand my own sickness.
Nothing good happens fast in an ecosystem.