user: Question: How many season 4 appearances are there by Mrs. Jennifer Knight?
Columns: ['Character', 'Played by', 'Season 1', 'Season 2', 'Season 3', 'Season 4', 'First Appearance']
Types: ['text', 'text', 'real', 'real', 'real', 'real', 'text']
Sample row: ['Kendall Knight', 'Kendall Schmidt', 20.0, 29.0, 12.0, 13.0, 'Big Time Audition']
SQL:

assistant: SELECT SUM("Season 4") FROM "Table" WHERE "Character" = 'Mrs. Jennifer Knight';