Can someone please explain Dinky Doo?

[Luminance 2,181]

I think that they both look very sisterly together but ever since Derpy and that other young colt are seen together in "The Cart Before the Ponies" and Dinky being with another mare (presumedly her mother) in "Flutter Brutter", I can assumed that they were not related to the level like the fans expected.

[Castle Bleck 19,166]

 

https://www.youtube.com/watch?v=aL3P-ObcmpQ

 

Am I the only one who wants to reach through the fourth wall and hug them both?

[TBD 17,228]

She someone unimportant

plus this is her older sister as it said in the wiki. And don't forget that Dizzy doo is just a nick name given by fans. Her real name is Derby

overall, they are all irrelevant to the story no need to dwell into much.

[Tacodidra 59,792]

I've always preferred the idea of her being Derpy's sister. I don't know why, but I feel Derpy is a bit young to be her mother (though it wouldn't be impossible). As for the idea of Derpy being Amethyst's mother, I can't imagine that at all (they appear to be about the same age to me).