The way around that is to use a CCW bag as a diaper bag. There are a lot of purse holster options that add structure to an otherwise floppy bag.
Attachment 93521
The combination isn’t much longer than a G34…
As to the revolver technique, I don’t use it but just as an illustration of modification of known techniques.
I don’t like that technique for myself personally because it compromises shooting mechanics and if I need to be shooting, that’s my focus.
I personally went for Bluetooth headphones with 23 dB NRR.
For the kid I would push them behind me if I they were older. And shield and turn like @
03RN said above for babies.