Theoretically, she’s correct.
Practically, it’s impossible to make a surface perfect enough. Any imperfections, down to the microscopic level, would be magnified by proportion to the amount of energy their being exposed to by the laser.
Say, theoretically, the spaceship only has 10m x 10m surface facing you, a very small surface area for a battleship. If there was only 1 sand-sized particle of imperfection in it, of not-perfect reflection, the entire armor would be rendered useless. Further, this problem is exacerbated by the fact that space isn’t actually empty. If any particles happened to be sitting on the armor, they’d absorb the heat from the laser, and likely melt into into the reflective shield causing an imperfection.
Yes, I’m nerdy. Yes, I’ve thought of this in the past. Yes, I’m damn proud of it.
ETA: So, that is to say, unless you’re assuming a perfect society which can build anything it can design, even in theory, and a society which has perfect deflection shields, then it’s practically impossible, although theoretically possible.