Oh yes, there were great differences between the two empresses.
I think because of their anti-german feelings, Alexander and Marie opposed Nicholas wishes to marry Alexandra.
Maria also feared that this minor little princess was going to diminish her influence with her son. But, Alexander being seriously ill and at death's door, they gave permission to the marriage.
After Alexanders death and the wedding, N&A lived with Marie at the Anitchkov Palace. Alexandra feeling very lonely and Nicholas spending much of his time with his mother,still grieving.
Alexandra was now the young empress and Marie dowager empress. Marie had constant frictions with her daughter in law. According Russian protocol the dowager empress had precendency over the reigning tsarina. Alexandra couldn't stand this, she also disliked Marie's influence over Nicholas. There was also a dispute
about the royal jewels. Marie had great taste for jewels,she refused to hand them over to Alexandra. They(according Russian protocol) belonged to the reigning tsarina. Alexandra didn't want them anymore, she didn't care much, but (again protocol) had to wear them at official ceremony's. Marie considered her daughter in law a stubborn woman, with narrow mind.
The "stiff englishwoman".
Marie was a sparkling person, who was fond of clothes and jewels. She loved social life, balls and parties. She was very popular in St. Petersburg society. As for Alexandra , she hated society life. She was not brilliant at conversations, shy, frequently ill. She disliked St.Petersburg and wasn't very popular among society.
Because of Marie's coldness towards Alexandra, the latter drew back from court.
Nicholas didn't ( or couldn't)do much about it.Het stood between his mother and wife, whom he loved both very much.
Both the empresses spoke to each other in polite but distant terms. There was no bond between these two women.