1.  I am looking for a book called, as I recall, A Little Country
Girl, published around the turn of the last century, I believe.  It is
about a "country" cousin who comes to visit her wealthy, sophisticated
relatives in their summer home in Newport RI.  The visit changes
her--and also the young people, who scorn her and her countrified
clothes at first.  The book has telling descriptions of Newport, and
of its summer style of life.   (It's not by Louisa May Alcott.  I
didn't find it at Powells, and haven't tried Amazon)
2.  Please find a book on etiquette for children published by
Time-Life Books around 17 years ago.

The price will be $25 for a successful search for each of these books.

Your first book is "A Little Country Girl," by Sarah Chauncey Woolsey,
who wrote under the pen name "Susan Coolidge." She is best known for
the popular girls' series "What Katy Did." Sarah Chauncey Woolsey was
a longtime resident of Newport, Rhode Island.

Here's a brief excerpt from a bio of the author:

"Circa 1872, the Woolsey family also built a residence -- a
high-ceilinged, book-lined home -- called 'The Jungle,' at 93 Rhode
Island Avenue, in Newport, Rhode Island, which remained Coolidge's
home for the rest of her life. (Newport also served as the setting for
one of her later children's books, A Little Country Girl.)"

19th-Century Girls' Series: Sarah Chauncey Woolsey
http://www.readseries.com/auth-bc/coolbio.html

"A Little Country Girl" is a delightful book, but, unlike the "What
Katy Did" stories, it has waned in popularity, and it is out of print.
However, used copies are readily available. Here you'll find a
selection of merchants offering the book for sale:

AddAll Rare, Used, and Out of Print Book Search: A Little Country Girl
http://used.addall.com/SuperRare/RefineRare.fcgi?id=050929141512166232 

The Time-Life book on etiquette for children is "Feelings & Manners,"
from a Time-Life series called "A Child's First Library of Learning."
You'll find several copies offered for sale at Amazon:

Amazon: Feelings and Manners (Child's First Library of Learning)
http://www.amazon.com/exec/obidos/ASIN/0809494833

My Google search strategy:

Google Web Search: "a little country girl" woolsey OR coolidge newport
://www.google.com/search?hl=en&q=%22a+little+country+girl%22+woolsey+OR+coolidge+newport

Google Web Search: "time life" children etiquette OR manners
://www.google.com/search?hl=en&q=%22time+life%22+children+etiquette+OR+manners

I hope this is helpful! If anything is unclear or incomplete, or if a
link doesn't work for you, please request clarification; I'll gladly
offer further assistance before you rate my answer.

Best regards,
pinkfreud