Oh lordy! Your poor mom!
Mine are girl 18, boy 14, girl 12, boy 4. Our oldest just got her first apartment....she wants a cornsnake for a housewarming present LOL! Our middle son and daughter are very good with the snakes. In fact, they are currently saving up to buy their own "personal" snakes - a female albino Nelson's Milksnake and a male het for albino Nelson's Milksnake. Our youngest is like yours and tends to move too quickly around the snakes.
I have to say I think snakes make excellent pets around kids (with supervision). It's been great for our kids to be exposed to a "pet" that they must adjust their actions around versus a puppy they can play with whenever they feel like it. They are learning more about patience, calm behaviour and putting the snakes needs before their own which I think is wonderful! They even tell their friends which days and times of day they can visit if they want to see our snakes....they know the "hands off" schedule down pat LOL.
One of our snakes, Rionach, seems to enjoy it when they pull up their shirts and bit and she can laze about on a warm bare belly while they watch a bit of evening TV. They know that a calm, quiet manner encourages a calm, quiet reaction in her. They start fidgeting around or being loud, Rionach moves off immediately. A very nice way to help learn the age old "actions cause consequences" lesson.
I think it's wonderful you are teaching your children the right way to be around Salina. Good for you! There's always some great life lessons when kid's interact with pets.
~~Joanna~~