I have not gone as far as your mom is planning. My son is almost 8, was diagnosed at 2, is my only child, and I am a stay at home dad still, so I am in a different situation. I would be willing to do different things, such as food recording, saline shots, and finger sticks, if I thought it would be helpful. At age 2 my son was dependent on my wife and I for everything. Although we don't have the disease, we understand it awfully well after many thousands of finger sticks, thousands of shots, and countless highs and lows, and one terrifying seizure. I will occasionally do finger sticks (to test for Type 2 diabetes) and have let my son test me or his mom. But, that's about the extent of it so far. I don't think my son would ask us to do something more than a finger stick but I would be willing to go along.
Having family members realize the frustration and angst that kids go through when they have diabetes is so important. Former Miss America Nicole Johnson had her fiancee wear an insulin pump with saline for one week before they were married so that he would have an idea what she goes through. Of course, the average person can't arrange to get an insulin pump and saline on loan.
You would probably have to get the saline from your doctor as I don't believe it is available otherwise.