Although you are right that Dwarven Armor starts to appear at level 6 , it is ONLY on
enemies and loot that you'll encounter during your travels. Dwarven armor is only sold in
shops starting from level 10.

The items that a vendor sells appear randomly , therefore you might not get a full suit of
dwarven armor on your first trip.

The vendors' inventory respawns every 72 hours.

go to visadale near imperial city, go thruogh the door amd make your way down tlii you get
to a room with umbra in kill her and rhen you get ebony armor(karl harvey) (lv 4
imperial)

Although you are correct that killing umbra for her armor will get you an "ebony" armor
but in reality if you acquire it before level 15 the umbra armor will be of orcish
strenght not ebony. So when you reach level 15 normal ebony armor will be in fact better.

But you are right , getting it at low levels make it , still , a very good suit or armor
for your character.

I believe though that the OP wanted the dwarven armor merely for estetics , not DR.