The things you said are exactly right so you do know what you are doing!
If you make something you can keep a portion for Leah in a tub in the fridge and it will be good for 24hours. Or as you say, stick it in the freezer and it will last a few months (stick label and date on) I usually defrost it by taking tub out freezer and leaving it in the fridge overnight, or use microwave to defrost and then heat til piping hot then let cool before serving especially if it has meat in - if its just fruit I just let defrost and then serve.
Ice cube trays are good. Put stuff in cubes and let cool (or let cool on worktop etc and then transfer to cubes. Stick in freezer. When frozen, usually around 5-10 hrs you can pop the cubes out and stick the cubes in a labelled bag so that you can use the tray again for making more cubes.
When I am making potatoes for dinner. I make lots extra and stick them in cubes and freeze. Same with carrot/brocolli. So, I make cubes of separate potato, vegs, meats, fish, pasta, pasta sauce, cheese sauce etc rather than actual meals in cubes. Then I can mix and match by selecting a few different cubes.
It is easy when you have started. I made a chicken dinner the other day and made extra potatoes and vegs too. Filled a few trays - that will last Anna for a couple weeks. It is so much cheaper too and maybe even better for LO. Some chicken dinners in jars have only 6% chicken!
Have fun