If you have access to a car in Boston, a trip to the Wrentham Premium Village Outlets might be worth your while. However, I do not know how pressed for time you are and it would be good to be able to devote the lion's share of the day to the shopping trip. There are many high end stores there that have women's sizes at reasonable, although not necessarily cheap, IMO, prices. What makes it worthwhile is all the major brands in one locale.

Hi all. Thanks for the great responses and so quick too. I have written a list to research further. I won't have a car anywhere on my trip. I will have some shopping time here and there during the trip:

LA - a day or so, Santa Monica and probably around West Hollywood way

Las Vegas - a day; along the Strip only

Boston - a day around the Back Bay area and Faneuil Market Place

DC - maybe no time, although will be near the Fashion Center Mall in Pentagon City

New York - this is my best opportunity with 7 full days in the city I'll be trying to get to stores of interest as I travel around.

As others have said, almost all major department stores have larger size departments. And don't overlook Target for casual clothes in larger sizes.
Rack Room is a shoe outlet type store.
Dress Barn also has a Plus size component.
In Vegas there is undoubtedly an outlet mall somewhere that would have a lot to offer.

The Las Vegas Outlet Center is just south of the Strip. It has a Lane Bryant outlet, Catherine's Plus and Dress Barn Woman, all of which cater exclusively to plus sizes.

http://www.premiumoutlets.com/outlet...ions.asp?id=61

OK, speckles, be sure to hit Filene's Basement on Boylston St. in Back Bay (or Newbury St., depending on which door you enter) as they have off-price items that often include designer brands. They have a good selection of larger size clothes. There is also a large Marshall's on Boylston that may have a nice selection--or not--hit or miss but the hits can be great!