If the number was clearly an international one then one has to pay what for what one uses. I assume the number was long enough, starting with a 00 (or maybe +) ? In which case the caller knows and opts to make and be charged for the call.
On the other hand if it was a national number which had roamed to Sri Lanka then the called party should have been liable for the forwarded portion of the call, and it ought not to have appeared on your daughter's bill.
The third option was that it was a premium rate number she called, I suppose, in which case the caller pays again.
Probably worth finding out the facts and querying your service provider, but I suspect your daughter's bill may be correct.