Well done Bev!
There's no way that nickname would have been used before her marriage to Steemson, so it doesn't belong with the Previous Name.
If we consider "Nana Steemy" to be a nickname used outside the
family, then what else is wrong with the way this notice has been indexed:
STEEMSON, Frances Marie (Nana Steemy);21SEP2016;(91);F;;
SCHLECHT, Frances Marie (Nana Steemy);;;F;see STEEMSON, Frances Marie (Nana Steemy);