Lots of engineering disciplines work this way. For instance, materials science is still crude, we don't have perfect theories for why some materials have the properties they do (like concrete or superconductors), we simply quantify what those properties are under a wide range of conditions and then make use of those materials under suitable conditions.

> then is raising a baby also an engineering discipline?

The key to science and engineering is repeatability. Raising a baby is an N=1 trial, no guarantees of repeatability.