There’s an easy solution to this, fortunately. You just have to take the switch that controls the current out of the picture and only use the button or another switch that works by talking to the hub which then sends a message to the Bulb…
There are two ways to do that.
First, depending on how determined your daughter is, you can just put a childproof lock on the switch. I understand that she might be able to remove it or might feel too frustrated by it, so that might not work for you, but if it does work for you, it’s an easy option.
The second is to replace that switch with something that looks like a switch but does not turn the current on and off. Instead, it works exactly the same way that the button does, by sending a message to the hub. Because the message is sent to the hub, you can put your time parameters on it.
Take a look at the FAQ for what kinds of switches to use with smart bulbs. (This is a clickable link) it’s the same solution, but for a different reason, people want to maintain constant current to the smart bulb so it can be turned on with the next network request. But there are a number of options. 
