Aerolopa provides the best visual of how the rows align: https://www.aerolopa.com/dl-3m3

What you proposed is probably the best option -- you should be able to lower the privacy screen between C/G so the adult and lean over and see the toddler.

If your kids were older, I would have recommended:

AC
AC

But having my own kid of that age at home, I can certainly understand the desire to have visual line of sight to them at all times

Shouldn't be an issue to share the bed with your toddler once the seatbelt sign is turned off, it just might be a little tight as noted above