Unless she’s an engineering or CS major, AP Calc AB is fine.
For a humanities kid, I would not take both BC and Stats next year – I think her time might be better spend with another humanities or social science class.
Don’t worry about either the rigor check box or about piling on more and more APs. It’s not an arms race. If she’s taking 4 APs in one year, she’s got more than enough rigor.