Yeah, sure, in this particular case it's no big deal. But if you allow this kind of treatment other teachers will only take it further. Eventually you'll have cases where kids will get injured. It's hard to enforce a rule where it's okay to use only a drop of soap, and no more. It's either all or nothing. If you allow her to use one drop, what happens when the next teacher decides to empty the entire soap dispenser in a kids mouth? It's a slippery slope, best to stay off it completely.
- Mike