Is it fair to say this to my spouse?

You can say anything you want to, but that particular tactic isn’t likely to work for you. Because not only is that YOUR motivation not your spouses motivation, it just isn’t the case. Many people work better with actual consequences rather than imagined possibilities. Now, you don’t say if your spouse works at a low paying job because it is all they are qualified to do or because jobs are hard to find or if they are just lazy, but the reason why they work at a low paying job matters. 

I’d suggest you sit down with them and review the household budget. Go over all the bills, the money coming in and the money going out, and let them know what part of those monthly bills they are responsible for paying for going forward. You may need to be prepared to set up a new bank account and only put the amount that covers your part of the monthly bills in it. If your spouse doesn’t step up their financial contributions, what are you prepared to do? Will you let bills go to collections? Incur late fees and damage your credit? Get divorced? Bottom line is that you can’t force someone to be responsible and if they know there is very little in the way of consequence to not changing their behavior they have no motivation to make a change.

I think it’s interesting that everyone assumes you are the husband and your wife isn’t contributing. In my household I make a lot more than my husband (who chooses to be underemployed) and support our family, so I understand your situation.

You have no right to try imposing your personal ideal or mantra onto your spouse. Be motivating to your spouse about a better paying job and the benefits he/she will gain from it. otherwise keep you superlative smart-*** comments to yourself.

i do not recommend using this tactic to get your wife more motivated, to get a better paying job, or for any other issue. You are free to share with her that this works for you, but you cannot "motivate" someone to do as YOU wish, look instead for means that involve what THEY wish. 

Speak to her about your concerns, ask that she share them. Getting jobs right now is at an all time low due to the pandemic. Have you agreed upon using a budget for expenditures? Perhaps this would be a good thing to do now. Good luck and good wishes,

No. But it's fair to work out a budget and explain to your spouse that you have "x" number of dollars for food/toiletries a month or a week and ask her to stick to that budget unless she can earn more money. Make her see how much money goes to bills and how much needs to be put aside for your childrens' education and your own retirement and healthcare needs. If you're supporting her mother also, she probably provides child care that allows your wife to work so you are actually saving some money by not having to pay for childcare that can be upwards of $10,000/year per child. Further if you do have built-in child care, then your spouse could really work more. Chances are your spouse had a low-paying job before you got married. This should not be a surprise to you. If you have a problem with the way she shops, when she is working also, then you can take over the family shopping to get these great deals that you think are happening. Is saving $10-20/month worth your marriage? But maybe phrase it in a way that she needs to work and be independent because you need to be able to save for the future of if anything ever happens to you or you become disabled that prevents you from bringing in as much as you do. You could be fired tomorrow. Have a joint account where you put in the weekly budget for groceries and then have a retirement account, an education account and keep some of your own money in your name only.  

No.  You're comparing apples to oranges.  Teaching yourself to use a stove is something that is done based solely upon you.  Getting a new job is much more complicated.  Most of the factors involved are outside of your control.  I have an MS in a technical field, and it took me two years after graduation to get a job - and it wasn't a great one.  We live in an area where the market is saturated with workers in this field (think Silicon Valley) and so there is a lot of competition for openings.  When I got my job, I was one of 50+ qualified applicants.  The position required only a BS in IS or CS, but most of us had an MS or Ph.D.  I could have easily gotten a job in my field if I had relocated to another region, but my husband also had a good job and couldn't move.  Job hunting has a lot of complicating factors.  Just thinking positive thoughts doesn't do anything.