Ms Blotter is now talking about getting into duathlons next spring.
Since a duathlon is a race, her touring bike will likely not be good enough. (it's too heavy, the gearing is touring not racing....) Sooooooooooooooooooooooooooo..... It sounds like after saying NO ROAD bikes, there's going to be some road bike purchase at some point in the future....
While my first answer is always buy another bike I'll play the devil's advocate today.
I could ride a full suspension mtn bike with 2 inch tires and probably finish in the top 60% on the bike section, maybe even top 50%. Unless the Mrs is a top duathlon competitor and is looking at qualifying for Cdn or Worlds is it really worth spending more money on another bike in the first year.
Her current bike is plenty fast enough unless I'm underestimating her ability to ride an average speed of 60kph. A 46x12 on 700x32's @ 90rpm = 44.4 kph. While there is no arguing that she would be "faster" on a real road bike due to being more aerodynamic how much faster would she really be?
If she is doing Olympic courses the bike section is 40kms long.
Time and avg speeds
1 hr 20 = 30.00 kph
1 hr 25 = 28.24 kph
1 hr 30 = 26.67 kph
1 hr 35 = 25.26 kph
1 hr 40 = 24.00 kph
If she isn't even doing Olympic distance races, spending money on a nice road bike is a waste. Every time I see a person in a tri-a-tri on a $10K TT bike with a skin suit and aero helmet I just want to kick them in the balls.
On a side note, I can't believe the prices of these races now. Sure glad I stop doing them.