594 reference here ... this is a simple interfamilial transfer so what does 594 have to do with anything?

That was in reference to if she wanted to sell/transfer it.

The definitions are pretty clear.

Section 921(a)(10),defines a “manufacturer” as any person engaged in the business of manufacturing firearms or ammunition for purposes of sale or distribution.

As defined by section 921(a)(21)(A), the term“engaged in the business” means, as applied to a manufacturer of firearms, “a person who devotes time, attention, and labor to manufacturing firearms as a regular course of trade or business with the principal objective of livelihood and profit through the sale or distribution of the firearms manufactured.”

You can make something without you being a manufacturer. If you start selling them without a 07 FFL then you are breaking the law, but you can make all the firearms you want for your own personal use.