If you wrote that you have "three ferrata sets" (I assume you meant three self-belay kits), I suggest getting or renting one more. Then everyone does self-belay, kids roped to you and husband more for sense of security than actual security. (Kids will surely feel safer, you two as well... even if maybe "just in the head")
If you want actual belaying, you would have to lead each section ahead (of course assuming "leader never falls"), make anchor and then with plate device belay child's ascent - and husband the same for the other. And that's really sensible only on most exposed parts, where kids will be scared and no ledge. Maybe you won't find such a part at all... because much depends on mental preparation too.
Try "rope team" first a few times on Pogačnik's path to Grmada (Šmarna gora) and then on a bit harder Gradiška tour above Vipava. Maybe there's similar elsewhere, but this first comes to mind. Kids will get feel for climbing on rock, you for belaying, rope length, time demands and such...