What episode(s) does Maggie talk in (if there are multiple please specify all that you know, thanks)

Answer 1

She first talks in the season four episode Lisa's first word(Dady) but no one hears her.  Other times she's talked but many are consdired non canon such as in treehouse of Horror lX when she talked like Kang.

Answer 2

She talks in the short "Good Night", "Bart vs. Thanksgiving", "Lisa's First Word", "Treehouse of Horror V", "Treehouse of Horror IX" and "Four Great Women and a Manicure".