Miss Manners: who can throw a shower?

[cereta]

DEAR MISS MANNERS: My niece has asked me for ideas for a baby shower she wants to give for her expecting daughter. I don't know how to respond without hurting her feelings. How can I gently tell her it's not proper for a mother to give a shower for her own daughter?

GENTLE READER: When you find out, please tell Miss Manners. She has been pointing this out for years, and it doesn't seem to help.