Ama Clutch is like a sweet counterpart to Nanny. Rather than gossip about sex with her young charges, she lectures them about chatting with boys while unchaperoned. Aside from giving us a different view of nannies, Ama Clutch plays two major roles in the book. She's at the center of both Glinda's character development and Doctor Dillamond's murder mystery.
It's this murder, and Ama Clutch's subsequent tragic insanity, that prompts Galinda's transformation into Glinda and Elphaba's transformation into a political activist. Though a victim, Ama Clutch accepts her unjust fate with resignation. Her deathbed interactions with her two "girls" strongly tie her to the book's themes of forgiveness.
"But the fault is mine --" began Glinda.
"You would do me more good if you hushed, sweet Galinda, my duck" said Ama Clutch gently . (18.104.22.168-4)
Interestingly, these ideas crop up again with Sarima. Both Sarima and Ama Clutch teach other characters, and us, a good lesson about how forgiveness can sometimes be given without asking, and how sometimes asking for forgiveness can be selfish. Way to go, Ama Clutch.