What should a woman do if her tongue accidentally utters a word of disbelief while she is reciting, and does this affect her state?

If what happened was due to deep contemplation and emotional engagement with the reading, then you must forget the matter and stop thinking about it to cut off the path of satanic whispers. One who narrates disbelief or reads it does not become a disbeliever, and likewise one whose tongue slips unintentionally. Uttering disbelief is permissible through narration and under compulsion, and a Muslim does not become a disbeliever by narrating disbelief.