There's also the fact that she is a female vocalist, with a quite piercing voice. Whereas Bob Dylan is a male vocalist with an old man's low deep growly baritone.
Even more so - and this is the most important thing - Bob isn't really singing on that track, so much as whispering into the mic. Whereas your singer is really singing and emoting.
They're polar opposites.
I would put a high shelf on your singer's voice, draw a small EQ bump and try to find a low-mid (or possibly even a high-mid) sweet spot that gives her voice a bit more warmth and body.
If you can't find it then I would re-track, and get her to sing a lot more quietly, which in itself will add a fair bit of bass. And concentrate on singing from her chest: take big deep breaths in between lines.
If the instrumentation isn't already panned hard left and right, then try it, and make sure her vocal is absolutely dead-centre. You could increase the delay between the left and right guitar, which sometimes creates the illusion of an even wider space. And turn the instrumentation down a touch.