Stoic wrote:

It's weird. My house is only about 2.5 years old. Water pressure is just
fine in the rest of the house but not in my daughters bathroom, and only
for the toilet and shower. The sink is working fine. The toilet
reservoir won't fill and the shower water pressure is low and I'm left
scratching my, er, head. Suggestions, observations, pointless comments
anyone?

I'll bet some "gunk" (technical term) has gotten in the lines.
Whatever it is chose the toilet and shower to settle in.

Try removing the shower head and see how the flow from the pipe is.
(Or just clean the head.) If there is good flow there now,
you'll have to take the toilet ballcock apart to clean. How you do
that depends on the model/mfr.

Jim