Even cheap file cabinets usually have a framework inside for supporting the hanging file devices. Check to see if Walmart has the framework separately.
There are other possibilities, but they all involve either carpentry or coping skills, and you're female.
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(That's a joke, son.)
Twenty years ago, I probably could have done it all and then some, but the years and CFIDS have taken their toll on my ability to do things and/or to figure things out. So you're right: I am female. And I'm still trying to find someone who has a drill so I can elevate the Laz-E-Boy onto a couple of 2X4's so it isn't so hard to get out of. I also need someone to drill a hole in one of the legs of the laundry cart and insert a long screw so the basket isn't permanently skewed.
I was spoiled for a good many years when I was younger, because as a military wife, I learned the only person I could depend on was me, and I could fix almost anything. Not these days...