I just encountered this sentence in the wild that showcases both について and は:
ことみくんは私について何か言っていたかね
If you translate very literally:
As for (は) kotomi-kun, on the subject of (について) me, did he say something?
But in a less literal translation you’d probably just say:
Did kotomi-kun say something about me?
The は kind of disappears in this translation and kotomi-kun becomes the grammatical subject, but the について is still present in the “about”.