Well the Travel Agent could not have booked connecting flights outside of the minimum connecting time set by the airport and airline, and based on a very high probability they will make it with no issues whatsoever, so you're being a bit harsh!

But if you want first hand experience, i've managed a 50 minute connection with 2 children, 1 in buggy, Y to Y with no issues. With 90% of passengers connecting, and mostly QR to QR, it is a finely oiled machine. Yes the bussing is crazy, 15 minutes to the terminal, a walk upstairs, and then 15 minutes ending up next to the plane you just left can be frustrating, but there were no issues. Every flight i've taken from Doha has left 15-20 minutes late - it seems to build in time, and colleagues have been on planes (to Bangkok) delayed an hour as so many people on were coming from Germany (holiday routes they often will for UK / German flights).

You even get priority boarding passes with lots of people employed to look out for you and push you in the right direction in the terminal.

Of course by the time your colleague flies (this Friday or another?) QR could have moved into their shiny new terminal with airbridges and everything.

To be honest, I wouldn't want anymore time than 65 minutes in the old terminal in Y.