ELO type question!

So lately I have gone through my provisional rounds and landed in bronze 4 (fml). Anyways my question is that anytime I go into a normal game with my gf who is around level 27, my team consists of under level 30's. At the same point the other team tends to have multiple silver players and sometimes gold 4/5. I have been testing this and its very consistent that I am always placed as the highest rank player against teams of people 5-10 tiers above me. Is this normal or does normal mode just use a different mmr?