The quick answer is yes, she can get to the same point using the steer-stub. In your case, add 5mm of spacers under the stem, and you need to find 5mm more reach somewhere in the stem or pads (i.e. a 125mm stem, or whatever adjustment is available to you @the pads to the tune of +5mm).
That's getting to be a pretty long stem, though. The fit chart for the 9-series bikes is based on what combination of SC RXL stem (and inherent pad stack in the SC bar) and frame size puts your pads in a nicely balanced place with respect to the steering axis. The relatively low profile of those TULA bars is what's driving your pad stack so low and into the small frame.
If you know she's going only ever going to be on the steer-stub for UCI reasons, I might approach the sizing a different way. A medium SC frame with a steer stub, 5mm of spacers, and a 73deg (or -17deg if you prefer) 105-110mm stem (the actual # is 107.5) also puts the bar center in the same point in space as on her small TTX with your stated stem setup while reducing the tiller effect too. If she later wanted to go non-UCI, a 100x10 stem with zero spacer stack will get her there on the medium, but with no room to move any lower.
It's something to consider, that's all. If she's happy on the 120 on the TTX, then a 125 on the small SC isn't really going to be that different.
Carl
Carl Matson
That's getting to be a pretty long stem, though. The fit chart for the 9-series bikes is based on what combination of SC RXL stem (and inherent pad stack in the SC bar) and frame size puts your pads in a nicely balanced place with respect to the steering axis. The relatively low profile of those TULA bars is what's driving your pad stack so low and into the small frame.
If you know she's going only ever going to be on the steer-stub for UCI reasons, I might approach the sizing a different way. A medium SC frame with a steer stub, 5mm of spacers, and a 73deg (or -17deg if you prefer) 105-110mm stem (the actual # is 107.5) also puts the bar center in the same point in space as on her small TTX with your stated stem setup while reducing the tiller effect too. If she later wanted to go non-UCI, a 100x10 stem with zero spacer stack will get her there on the medium, but with no room to move any lower.
It's something to consider, that's all. If she's happy on the 120 on the TTX, then a 125 on the small SC isn't really going to be that different.
Carl
Carl Matson