Xxx "Reached daily limits" and has been locked. but child has 24 hours...no time limits

My daughter (only one of the 3) keeps getting the message that shehas reached her daily time limits and gets locked out of her logon. She has no daily time allotment. She ahs curfew hours, but no daily time allotment. It is only one of my kids. The all have the same time settings. Please help.