From one novice to another....
In our limited experience you just let them get on with it, perhaps keeping a slightly watchful eye. We had two ewes in lamb this year, and they had their lambs within a hurdled area, adjoining the rest of the flock. Once lambed, they rejoined flock. First one (had much earlier lamb) began a fight with every single other sheep (be it ewe, hogget or older whether), which was horrid to watch and not intervene, but when she'd finished them all off (!) she just lay down in middle of field and had an undisturbed sleep - obviously confident that no one would try to bother her or her lamb ever after.... clever mum! Second ewe was less confrontational. Both are 9 years old, so very confident mums, and they joined a flock which included a number of 18 month old ewes who wont be mum until next year....
Our main flock are Balwens (welsh mountain sheep), but we also have 6 18 month old shetland girls who were brilliant birthing companions, and never caused any trouble at all...
good luck