Perdita (mom) here-
I include myself in this category (to say the least) and with Mother’s Day approaching I thought I would give some ideas to get for your mom/wife.
The gifts can be purchased at the parks, online on Disneystore.com, or from other online stores.
One gift idea that I think would please any mom is a Disney print. These come in all sizes with about every Disney character imaginable. I have purchased several at the Disney Parks at Art of Disney in Epcot and at The Magic of Disney Animation Gift Shop in Hollywood Studios. They sell prints in the stores and have kiosks where you can look through hundreds of prints. There are three major types of art: pencil drawings, canvas-wrapped art, and prints that need framing. A fourth category that I purchased once was a cel ( animation in which the animator painted the Dumbo in by hand and the rest was a print). I should add that you don’t have to go to Disney World to purchase Disney prints. I have found them reasonably priced on Amazon.com and have bought one from Disneystore.com.
One other idea that is much less expensive and doesn’t have to fit (like an article of clothing) is kitchen accessories. There are mugs,dishes, glasses, pot holders, kitchen towels, wooden spoons, measuring spoons, etc. For me, it brings a little Disney “magic” home with me and a smile to my face when I see ( for instance) the Mickey measuring spoons or a Winnie the Pooh coffee mug. If you are at home there is a wide selection of items at Disneystore.com and free shipping is available for purchases greater than $75. Sometimes they have other free shipping offers for any purchase amount.
If you can discern the taste of your mom well enough Disney has a lot of jewelry available for a wide range of tastes and prices; from watches to Pandora jewelry to earrings, etc.
Clothing is available from many vendors besides Disney for sometimes a considerable cost savings from Target to online merchants like Zazzle. This is a trickier purchase due to not only taste considerations but the fit of the clothing. I would caution staying away from this type of purchase unless it is a basic t-shirt or pajamas.
Disney also sells handbags with a wide range of prices; from Dooney and Bourke designer bags to simple totes (which I returned home with on my latest Disney trip). Luggage is also a good gift idea but it comes at a high price for Disney luggage ($150-$200).
My favorite idea and I think the most fool-proof: knick-knacks or figurines. I have several with Winnie-the Pooh and Peter Pan, Mickey Mouse, Mr. Toad, Dumbo, etc. These come in so many prices points and with so much selection from so many places the choices are dizzying. (I scored major deals a few months ago at a local Hallmark store when I went in the store with no idea of the selection or the deals).
This is by no means an exhaustive list but is a good start. Again, these items may be purchased at the Disney Parks or ordered online from Disneystore.com or many other places like Amazon, Zazzle, or many others. Some items can be found at local stores such as Target, Hallmark, or the Disney Store. 
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