And here we have the Apple family: (from left to right) Applejack Apple, Jazz Apple, Ruby Red Apple, Jonathan Apple, and Rarity Apple
Backstory: The funny thing about Applejack and Rarity is that the two of them never formally dated; their relationship prior to their marriage was basically 1) They would be having a perfectly fine time with each other, 2) there would be some misunderstanding, or one of them would say something, that caused a rift between them, 3) they'd proceed to ignore each other and only communicate through passive aggressive insults, 4) some terrible disaster would occur that would force the two of them to put aside their differences and work together, 5) They'd make up, and by "make up" I mean "verbally apologize and then proceed to roll around in the hay all night long", and then 6) repeat several times. This kept going for years until one day Applejack finally got fed up, stormed into Rarity's boutique, and demanded to know what they were. In that moment Rarity pulled out an engagement brooch (for Applejack to put on her hat), and said "Well, I was hoping we could be engaged". After spluttering like an idiot for a good few minutes Applejack managed to squeak out an "Ok, sure >///<", and the two went on to spend months arguing about what kind of wedding they should have until they finally settled on a simple affair in one of Sweet Apple Acres' fields.
It wasn't long after they got married that Rarity asked Twilight for the gender-changing spell that Twilight used on Rainbow, and after making sure she had the spell down pat, used it on Applejack (with her permission, of course), for some well-mannered "fun". Course this ended up leading to Rarity becoming pregnant, and a year later she birthed their eldest daughter, a unicorn named Ruby Red Apple.
Ever since she was a filly Ruby has been very mature for her age; she's almost always the voice of reason, the shoulder to cry on, and the best pony to go to for advice. She is a very sweet and tender being, and takes pride in being able to help others with their problems (Applejack swears that she must've gotten it from her aunts Sweetie Belle and Applebloom). Both Rarity and AJ greatly encourage their daughter to pursue her passion of helping others and making the world a better place, however Applejack does somewhat wish that her daughter would take a bit more of an interest in the Apple Family trade ("Come on, Sugarcube; yer wasting those strong legs of yours on just walking around town. Just try buckin' a few trees, fer yer dear ol' ma").
Once Ruby was about school age Rarity and Applejack were hit with a massive wave of baby fever, and employed the use of the spell again (this time using it on Rarity) in order to conceive their second child, a little earth pony named Jonathan Apple.
Jon is, to put it in simplest terms, a bit of a spoiled child. He's not necessarily bratty, but he can be quite vocal about his displeasure with things from time to time. AJ blames it on Rarity, saying that ever since Jon first entered the world she's been doting on him and running to his every beck-and-call. Jon inherited none of the Apple Family strength, but he did inherit mama Rarity's keen eye for all things stylish, and he uses that to create his own little dress and suit patterns for his dolls (or "miniature mannequins", as he insists ponies call them). Whenever Jon is creating new outfits he is very quiet, going completely into his own little zone, from which it may be hours before he emerges from it, with new clothing in spades. When he's not designing, however, he can be a bit of a nuisance (kind of like when Sweetie Belle, back in her foalhood, would constantly bother Rarity), and Applejack swears she's gonna whip that boy in to a properly behaving gentlecolt if it's the last thing she does.
When Ruby just became a teenager, and Jon was going in to school, Rarity and Applejack used the spell once more (this time on Applejack again) as a little something special to spice up their Hearts and Hooves Day. This ended up backfiring on them when, once again, Rarity came up pregnant. Several months later they had their second daughter, and their final child; another little unicorn girl named Jazz Apple.
Ruby, Rarity, and AJ instantly fell in love with Jazz, but Jon did not. He didn't like the idea of not being the baby of the family anymore, and proceeded to throw many fits and become exceedingly resentful of the new baby. Even now that Jazz is no longer a baby, but rather a small child, Jon still dislikes her. Rarity takes this as a chance to continue coddling her son, and reassuring him that both she and his ma love him, however Applejack is near fed-up with his behavior (especially since he is well into school now), and constantly tries to insist that it's time for some tough love. Of course, this isn't to say that AJ doesn't like Jon; on the contrary, she very much loves him. She just doesn't like the kind of spoiled brat that he's turning out to be.
Though Jazz is still developing a personality, it seems, with the amount of questions she asks about apples, and the fact that she's constantly joining Big Mac and AJ on trips out to the fields when they're harvesting, that Applejack has finally gotten her wish of having a child who'll go in to the family trade.
Ruby gets along great with both of her mothers, and she and Jazz have a good relationship, but Ruby gets annoyed with Jon quite easily. Jon loves both of his moms, but very obviously favors Rarity; he looks up to Ruby (though this doesn't stop him from annoying her), and he very much dislikes Jazz (though he would never hurt her). Jazz loves both of her mommies very much, but things are kind of distant between her and Ruby, since Ruby is so much older than her. Jazz very much adores her older brother, and doesn't understand why he doesn't like her.
Sidnote: Applejack is "Ma", and Rarity is "Mama"
Well, 2/3 down, one more to go: The Pinkieshy Family <3
