"World Reserve Monetary Exchange" is an official-sounding name, and that seal looks all governmenty, but they are not connected with the government, the Federal Reserve Bank or the Bureau of Engraving and Printing in any way. They're just a private mass-marketing company. As such, the paraphernalia packaged with the notes by this company doesn't significantly increase the value, and the "certificates of ownership" supplied by the company are pretty but meaningless pieces of paper.
In other words, the value of the "Set" is exactly the same, whether you keep the notes in the folder or take them out and throw the folder away. The folder has "done its job" of protecting the notes well enough and does not seem to be made of harmful plastic, so I wouldn't actually recommend throwing it away unless you've got a more protective, more compact method of housing the sheet of notes. Unfortunately, your mother probably paid a considerable premium for all of that redundant packaging.
The World Reserve Monetary Exchange seem to still be in business. Funnily enough, going to their website you can't find any of their products for sale there; it's only a Customer Support page for people who want to try to get their money back.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis