Too much thinking and pontification here. The short answer is yes, If you put her tires on your bike and your tires on hers, your positions would be approximately reversed. Somewhat narrower, less-heavily treaded and higher pressure tires on her bike will make it easier for her to keep up.
Your tires will go on her rims and fit on her bike, so you could swap them and see how it works. Hers will go on your rims but might not fit in your frame (I don't know how much room there is on a Sirrus). That's a 20-minute experiment that will answer your question, plus being good training for the inevitable flat tires to come.