A few observations...
You mentioned that you want sharper images and you also mentioned a zoom. Without paying a fairly premium price a zoom lens that will give you significant "pop" will be hard to find unless you stumble upon a really, really good deal. If the 17-55 f2.8 is to expensive then you might want to re-evaluate things. The 18-135 f3.5 is a pretty good performer, it is also an EF-S (crop) lens so it won't bridge over for use with full-frame cameras. It's not the best low-light lens, though. I've got one of these that I am going to sell (actually have two). Also the Tamron 28-75 f2.8 is a fairly decent lens, not the peak of quality but a very capable lens...I have one hanging on the front of my 6D...it works on either crop or full-frame cameras.
You mention that you're planning on a business. You mentioned, also, that you didn't particularly care for bokeh....the thing is, though, that many of your clients *will* like it...you can always tighten up the aperture to lose the bokeh but if the camera isn't capable of good bokeh to start with you can't "create it from nothing".
Since you have shot some at the 55mm end of your kit zoom and you mention that you want to get "closer" then I wouldn't opt right now for the 50mm "nifty-fifty". You appear to need to go longer. The first prime lens I would look at would be the 85mm f1.8 (as I've mentioned before). It's image quality is very, very good for the investment..sharp, crisp, clear. When used on a crop body it's field of view is equivalent to a 135mm which during the era of 35mm film cameras was the "go to" portrait lens. Portrait lenses usually range from about 80mm to 135mm...the reason is that facial distortion is at pretty much a minimum in this focal length range. You will definitely get "closer" with the 85mm on your crop camera and later if you buy a full-frame body it will be a fine lens on it as well.
Will your friend let you use her longer zoom to see how you like it? That lens is also a kit lens...remember you said you wanted "sharper". Primes are the quickest path to "sharp"....less glass and tubes to get out of line.
Remember, too, that with longer lenses you need more working room.
Ah well, seems there was something else I wanted to say but it slips my mind. These were a few thoughts...and they are worth at least what you paid for them.