No, not a 48", if you want to be technical, since 36x18 is the minimum, 4'x2 being the reccomended size for one, to be able to house two females comfortably you would need a minimum of a 100 gallon tank, that still giving each one less than the reccomended minimum square footage they need. A 125 is the smallest tank that you could house 2 in with giving them each the reccomended space.
Needless to say, you don't want to house together. It's not worth the risk. After I got my first beardie I wanted another, but didn't have the money since the initial setup for my first, plus the cost of the actual beardie. My first is a female, so I could have done what I wanted and bought another female and just put her in with my other so that I could have two and not have to buy all the essentials for another tank, but I knew I would be happy, but that meant taking away from girls happiness to fulfill mine. Well, I put my beardies needs ahead of mine, waited a few months and saved extra $, then when I could give another beardie everything it needed plus some, I got another. And I couldn't be happier that I waited and did what was best for my beardies. Now I have 2 happy healthy little boogers eating me out of house and home, but I wouldn't change it for anything.
Not even thinking about the fighting, missing toes & limbs and violence that comes with housing together, if one gets sick, they both get sick, then you have 2 outrageous vet bills.