CREATE TABLE table_1813 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "U.S. viewers  ( millions ) " CLOB)

How many millions of U.S. viewers watched the episode directed by Allison Liddi-Brown?
SELECT "U.S. viewers (millions)" FROM table_1813 WHERE "Directed by" = 'Allison Liddi-Brown'
SELECT "U.S. viewers (millions)" FROM "table_1813" WHERE "Directed by" = 'Allison Liddi-Brown'