I measured the scoop I get with my Chondroitin/MSM. It is one level teaspoon.
My directions for a maintenance
dose is one scoop (one teaspoon) daily. I can feed two scoops daily if needed.
The chondroitin sulfate is 3000 mgs per scoop and the MSM is 7000 mgs per scoop.
Just feeding one horse one scoop daily, one pound should last a couple months or longer.
You might call the company ask them how many mgs of MSM per scoop.
My vet won't let me feed any of my horses more than two scoops daily on a regular basis which means 6000 mgs of chondroitin and 14000 mgs of MSM.
These are NSAIDS that a horse can stay on long-term but they are not something that should be fed past the maximum daily dosage recommended by the company.
Conversely, you don't want to feed less than the minimum either - they are meant to be fed every day once the routine is started
I hope this helps and I hope it makes sense; if not show this to your mom and/or ask more questions