First, you need to check local code for fencing associated with a pool. In our area, it is 60" minimum plus a spring closure on the gate. If so, your 48" fencing might not be code and could be a liability in case of an accident. Pools are considered "attractive nuisances" which means you are ultimately responsible if your fence is too low.
I used your excellent pic to sketch out a solution (using a low fence design per your post). You can see how I ran the fence into your existing steps on the right (an inspector might comment on that positioning) and into the hill slope on the left. My idea is to run the fence into the retaining wall and starting the fence post (above it) from that point. From there, the fence sections sit inside the wall, approximately level at the same horizontal elevation into the backyard.
Odd, of course, because the height of the fence in back is HIGHER than the fence in front. Guess you don't want those pesky deer getting in your pool ...
How does this work for you?