I’ve just made a dress that buttoned up the front for a Highborn who is breast feeding.
As an imperial orc I suspect you won’t need the buttons, a cross over front robe is probably easiest, with OOC supportive underlayers.
For very tiny babies a sleepsuit in a plain appropriate colour for your nation is fine, and the easiest way to carry them around seems to be baby wearing.
Next step up is very basic t-tunics over sleepsuits again. Just make the head hole much bigger than you would for a proportional adult one.
They’ll be Ok in tunic over leggings until about 5 or 6 when they will probably have opinions on what they want to wear, and will hopefully not grow out of it half way through the year.
To be honest though the comfort of your little one comes first, and all in one fluffy suits for cold evenings will not be mentioned, apart from 'aren’t they cute!"