With humans, we can even imagine that mother body teaches child brains via placenta or something (I don't think that's what happening, but whatever).

However think about birds. They lay eggs. So there's no direct connection between mother body and child body. Yet it works somehow...

The yolk (used directly in the embryos development) is generated during 10 days (https://www.purinamills.com/chicken-feed/education/detail/ho...). This could give the opportunity to pack a lot of "indirect information" to be used by the future embryo.

Regarding "teaching" the child while in the womb, it is exactly what is happening, see: https://www.americanscientist.org/article/baby-talk

I do agree that some organisms will transmit more "information" (via multiple ways, chemically, mechanical, etc.) than others (like maybe the birds) but the fact is the DNA is just a part of the development process and even if maybe it is "the first one", it will not "pack" everything.