Hey, homeschoolin' mom! Way to go. I have buddies from church who homeschool.
Anyway, since you "teach"
, you know how to read and do math, so just do some research on what you can add to what solvent to get a reasonable facsimile of MediFast or Wonderslim. For folks used to cooking and divvying up portions, it's EASY.
The good thing about doing it yourself is you can avoid what you dont' want. WonderSlim has aspartame. Medifast (and Wonderslim products, some) use soy. I don't like either, eh...
So, figure out first the numbers on Wonderslim shakes (or whatever plan you wanna follow). That is, calories to carbs to protein to fat.
Don't worry about nutrients or fiber, as you can easily take a multivitamin and fiber supplement as needed. Those about everywhere. Wonderslim ain't high fiber, anyway. (Medifast provides a lot of fiber, though.)
Choose a solvent. I'd consider water and unsweetened low carb almond milk as good possibilities.
Consider a protein. I like BSN Lean Dessert--good flavor, affordable if you shop around online and find a sale (like on Drugstore dot com or Amazon dot com). Consider how many servings you get for what dollars.
If one is heavy in nutrients, you might be able to HALVE the scoop portion and get WonderSlim calorie/carb/protein/fat (or close) rations. Keep to lower carb options, obviously.
If you want to go even healthier and CHEAPER, buy the unflavored whey isolate, add your own flavors (extracts or actual chocolate, raw cacao, etc).
In other words, with water and flavaored protein mix OR with almond breeze and unflavored whey or other protein (almond breeze comes in vanilla and chocolate) and with your own sweetener, stevia or sucralose or whatever, you can devise your own protein shake equivalents that fit the WonderSlim parameters.
You just have to do your homework to find what works, what you can save on buying in larger cannisters, make the ratios work.
It's easy but time-consuming. But you can do it.
As far as the soups and snacks and stuff, that would mean more shopping around to see what low-carb options are similar and more affordable, or just make your own do-it-yourself (scour web for recipes for low carb soups with the profile). Make your own low-carb protein hot cakes. Etc.
It'll probably taste better than WonderSlim's if you do it to your taste, and STAY within the plan and numbers.
The place to start is by going to DietDirect's site, loooking at the products, looking at their diet plan in the pdf file link provided, cut and paste the nutrient profile for the main nutrients, and then find copycats or make copycats.