Size 18 onwards can normally be considered plus size womens clothing,
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
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.
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.
Queen size in women's clothing is what is commonly referred to as plus size clothing. This ranges from 2X to 8X and are reserved for women with big bodies.
Size 20 womens pants are what size in mens clothing
Plus size label is usually marked with a W after the number. The sizes range from 14W to 32W
Myles Ahead is one such store in Florida. Here's their location page: http://www.mylesahead.com/store.cfm
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/
you can find attractive plus size clothing from my moms and all her friends's favorite site http://www.lanebryant.com/ to find your stylish plus size clothing :)
One of the best places to find inexpensive plus size clothing is from Target. You can also go to OldNavy.com to browse Old Navy's selection of budget-friendly plus size clothing.