One of the best places to shop online for beautiful plus size clothing is Torrid. You can find everything from cute tops to pretty dresses. The website is available here: http://www.torrid.com/
overstock.com should be helpful in allowing you to find the best prices for plus size clothes, and it offers an extensive selection of outerwear. With this website you can compare prices and the quality of clothes to find the best fit for you.
Here are a couple places you can buy plus size clothing: http://www.avenue.com/ and http://www.roamans.com/ .
You can find plus size clothes online from any major retailer. You can also shop at Wal-Mart or target stores online. Also the gap, or any outlet malls.
You can go to Amazon and search for those size in clothes.
There are many clothes lines that offer plus sizes. Oldnavy.com also has great prices, clearance and has plus size clothing. Cato is another great store.
You can easily find plus sized womens athletic pants in different online stores like the "SimpleBe" website. It has sizes from 14-32. You can also try JD outlet stores as they usually offer plus sized athletic wear.
There are a nubmber of websites that have plus size belts. I thought this was infomative on how to choose and who sold them. http://plussize.lovetoknow.com/Women%27s_Plus_Size_Fashion_Belts
You need to watch your budget and find great tops for your mom. You need look no further than Trendy Plus Size Clothing: http://www.avenue.com/womens/clothing/trendy-plus-size-clothing
A popular location and can be accessed across the country and online is at Old Navy. At www.oldnavy.com you can find yoga clothes ranging up to a size 28.
Macy's does carry plus sized women's pants in the stores and online. Their catalog is right here for plus sized clothing.
Yes, one can find plus size clothes at Coldwater Creek. The selection is not as extensive as petite or regular sized clothes, but there are plus sized options.
Roamans.com is a store that offers a lot of different clothes for plus size women. They also seem to ship internationally. They also seem to make some quite stylish clothes!