"but nobody seems to know how the wages work out, whether or not they pay 'standby' when its school holidays, and how many hours I might work."
That's your answer and your email.
"I'm sorry but I just haven't had enough information about this to feel confident that I could do the job to my own (and your) satisfaction. For instance, nobody seems to know how the wages work out, whether or not they pay standby when its school holidays, and how many hours I might work. So reluctantly I must decline this offer but please feel free to keep me on your list for further work"
Don't let it scare you - you just don't come across as a lady who scares easily but we all have our vulnerabilities. 
Accents - a privilege to hear them



