Who is Sunny Baudelaire from The Slippery Slope and what is their importance?

Sunny Baudelaire is the youngest of the three Baudelaire children. Though only a toddler, she is smart and resourceful. Sunny has an unnaturally large set of teeth, which she uses to bite through things, and she speaks in a way that only her siblings fully understand. Sunny also uses her appearance as a kind of disguise, fooling Count Olaf and his followers that she has the intelligence of a baby when she is actually plotting to learn his secrets and help her siblings stop his plan.