Oh my GOD, what a NIGHT. This is my worst nightmare as a carpooler -- that I'll flake out. I worry about that much more than I worry about the other parent flaking out.
FYI, Virgin Wireless sells very cheap pay-as-you-go phones that are very economical for occasional use. (Mine cost $20. Ed lost his and was able to buy a refurbished replacement for $8 via their website. The minutes are expensive but if you use it only occasionally, it's the cheapest option I've found.) If Fiona would use up the minutes texting friends and then be unable to take your calls because she was out of minutes, there's a cell phone company that sells pay-as-you-go phones that have multiple "wallets" with restrictions you can designate. So for example, you could have a wallet that refills off your credit card that can make and receive calls to a set list of numbers (all family members, grandparents, emergency contacts, etc.) and a separate wallet that she has to buy minutes for that would be used for all other purposes. You can also set it to allow calls to/from only pre-approved numbers, you can set it not to work during school hours, there are all kinds of options. It costs more than a Virgin phone, though, I'm pretty sure.
That won't fix the "signal can't get into the high school" problem, though; that tends to be inherent to big, heavy, brick buildings.
no subject
FYI, Virgin Wireless sells very cheap pay-as-you-go phones that are very economical for occasional use. (Mine cost $20. Ed lost his and was able to buy a refurbished replacement for $8 via their website. The minutes are expensive but if you use it only occasionally, it's the cheapest option I've found.) If Fiona would use up the minutes texting friends and then be unable to take your calls because she was out of minutes, there's a cell phone company that sells pay-as-you-go phones that have multiple "wallets" with restrictions you can designate. So for example, you could have a wallet that refills off your credit card that can make and receive calls to a set list of numbers (all family members, grandparents, emergency contacts, etc.) and a separate wallet that she has to buy minutes for that would be used for all other purposes. You can also set it to allow calls to/from only pre-approved numbers, you can set it not to work during school hours, there are all kinds of options. It costs more than a Virgin phone, though, I'm pretty sure.
That won't fix the "signal can't get into the high school" problem, though; that tends to be inherent to big, heavy, brick buildings.