Maybe it is somewhere in the text and I've missed it, but I'm wondering how Aaron, his brother, avoided death?
There is no way to know for certain, but most likely Aaron was old enough that Pharaoh's command, “Every son that is born to the Hebrews you shall cast into the Nile..." (Ex. 1:22), did not come into effect until after Aaron's birth.
In Exodus 7:7 we find out that Aaron is 3 years older than Moses, "Now Moses was eighty years old, and Aaron eighty-three years old, when they spoke to Pharaoh."
We don't know how long this decree was being enforced, but it must have started after Aaron's birth, which was 3 years before the birth of Moses. Another option was that Aaron was born when Pharaoh had placed the mid-wives in charge of killing the baby boys, and they were not very good at it (Ex. 1:15-22).