Is it a random tournament, or some national regional thing where winners go on to a true national tournament?
Is your daughter one of the stars or more of a role player?
How many games, and how much would she play?
Is there a shortage of players and they need everyone there?
What does she want to do, assuming it is pain management?

Ideally, doctor gives green light with "no further toe damage", and then you can test it out yourself. it's unfortunate that you can't be there, but perhaps you can tell coach along the lines of "Doctor approved. it's still tender, so I don't know how much she can play, especially if there are multiple games. Since we're not going to be there, I've asked Ashley's mom to try to check on her..."

If you're worried about how she'd handle it without you, I'd either try to get to at least the first game myself, or just keep her home and call it "doctor's orders". "Yeah, doctor did say it was pain management, but she couldn't guarantee that she wouldn't do further damage. I'd rather have her healthy for the next tournament than have this lingering toe issue for the rest of the season"

Good luck.