I would say that you are correct. For low Quantity, it may be possible to preserve some quantity to enable use the brakes.
Once the system has low Pressure (from loss of quantity), this is no longer possible:
Normal brakes and alternate brakes from center hydraulic source are inop
Alternate brakes from the reserve hydraulic source are available.
It's been a while since I looked at this scenario, but with low Pressure being consequential, if you hadn’t already started the low Quantity checklist, it is not required.
Since this was presumably in a Sim, you will already know who is “correct”.
Good luck.