I'm moving to a new city and setting up work in advance. I was originally going to split my time between two families, but one of them fell through. I was already planning to be with the other family 2 days a week and now that the other position fell through they're asking about keeping me on-call for two more days a week. The grandparents usually watch the kids those days, but apparently they travel sometimes and the parents like the idea of knowing that I would be consistently available to pick up days if needed. So the majority of the time it would only be two days a week, but sometimes 4. It would typically be a 9-hour workday.
How would you handle this? What would be standard? They were asking about a flat rate per week to cover it, but I don't know how that would work. I was thinking about purposing that they pay me my usual hourly rate for the days that I work, and 50% of my rate for those days/hours that I reserve to be on-call for them. Then if they do need me, they pay my usual hourly rate for those days. Would that be a reasonable arrangement?
I'm trying to figure out what would be fair for everyone. I know that in the past I've sold myself short and charged much less than I should have. I feel like I have a more appropriate hourly rate now, but am really unsure of how to set something like this up. I know my tendency is to be a pushover and accept too little. I would really appreciate input from others!