I'm not 100% sure what you mean by "outlines". If you mean sewing patterns, there are sites where you can get those. Here are a couple: http://plussize.lovetoknow.com/Free_Sewing_Patterns_for_Plus_Size_Women and http://www.sewgrand.com/ .
Size 18 onwards can normally be considered plus size womens clothing,
You should look for Plus Size Clothing stores. Avenue Plus size clothing on Brodie Lane And Southpark Meadows Shopping Center are two of such shops. I would suggest looking at www.filthyrichfashions.com. And beleive it or not you can find a good selection of big and tall womens clothing at Walmart.
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
There are several options availble for you. I highly suggest the following: www.lanebryant.com/, www.alight.com/, and www.avenue.com/womens/clothing/plus-size-clothing-sale .
Lane Bryant is a very good store for plus size clothing. They also have great prices on good quality clothing. They are in most towns.
Myles Ahead is one such store in Florida. Here's their location page: http://www.mylesahead.com/store.cfm
FInding nice plus sixe clothing can be hard. In New York I would suggest Ashley Stewart Women 488 Fulton Street, Brooklyn - (718) 246-1067
The Tahari brand of clothing offers plus sized women's suits. Find them at retail outlets such as Overstock, and traditional stores like Bloomingdale's.
There are severals stores in the Bay area that have plus sized women clothing. One would be Avenue and another Catherines. They have both a good and trendy collection for plus sizes and something for every taste.
JC Penny and Sears both offer plus sized clothing for women. Prices vary based on the type of clothing.
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/
Macy's does offer a relatively large selection of plus sized women's clothing. They carry clothing lines like J Jill that offer very stylish clothes for the plus sized.