Nice to know that Rarity DOES have family. A lot of 'fic writers have either assumed they were dead, ignored their existance or non-existance entirely, or went the route of "Rarity is 'secretly' Sweetie Bell's Mom".
It also indicates we might be seeing the rest of the families of the other Mane 6.
Though, the new opening has brought up an interesting Fridge Logic moment: In the background as Twilight gets off the balloon, we see a train with a pony as a proper engineer. Yet, in the previous season, we saw four ponies pulling a train.
I have to wonder if they'd taken to pulling the train because the Buffalo were able to disable the train if it was using it's normal coal or if it was to keep the surrounding air clean for their cargo (the apple tree).