I also carried (and still do) my daughter quite a bit, first in carrier (Ergobaby), then backpack (Deuter 3 for 150 € on Bolha (on Bolha you find very very old versions of this backpack too, helpful - if backpack already has footrests for legs it's ok).
But 6m baby definitely not big and stable enough for backpack. Use carrier instead. Backpack recommended only when child sits up and sits alone (not when you lean it somewhere and it stays all hunched). So around 8m.
My favorite quick route is Jošta, for more demanding Begunjščica, Veliki vrh, Storžič (if not bothered by very high leg lifts - this route too hard for me with 15kg on back).