Of all my odd headcanons for MLP, I think the ones surrounding Dinky are my favorites. I'll have to do a picture with Dinky's whole family to explain all of them, but this odd one makes for a good first.
I fell in love with this pairing because of a fanfic (and its sequel). I'm sure every other sailor on this ship knows which one. I'm still working out what Pipsqueak does when he grows up, but after his most recent appearance, I could see him possibly running for mayor. Dinky works with her step-sister, Noi, using her talent with magic to make things that make ponies lives better. (eg. better magical batteries, prosthetic limbs. They're even close to having a prototype functioning artificial horn for unicorns that have lost their magic due to injury or genetic defect)
Dinky and Pipsqueak had a little trouble trying to conceive. Eventually, they started to accept the possibility that they might not have any children of their own. It was a very trying time in their marriage.
Then one day, they happened upon a young diamond dog pup, probably not more than a few days old. He was young enough that his eyes were still closed. He had probably been abandoned because he was the runt in a litter that was just too big. They took him to the vet, who gave him maybe a week to live at best. The little guy kept fighting, though and soon grew to a healthy size and weight. They reached out to the kingdom of Dimondia, but none would take him, so Pip and Dinky agreed to adopt him, giving him the name of Bo (meaning 'living').
At first it was sort of like they were pet parents but as he grew they started thinking of him more and more like an actual son. When he learned to talk, it felt natural for them to try and get him to say mama, dada, and all that.
Bo is very curious. He isn't the sharpest tool in the shed, but by no means is he stupid. He has some difficulty picking up on Equestrian social cues, and he's got a bit of a learning curve, but with proper guidance, he does just as well as the ponies his age.
A few years later, Gusty came along. I haven't decided if Gusty is biological or if Pip and Dinky decide to adopt again. Bo absolutely adores his baby sister and does everything he can to help around the house. Gusty thinks he's the best big brother ever, so much so that she's been known to be quite defensive of him when he gets picked on, to the point of picking a few fights, for which she is promptly grounded.
Cutie marks courtesy of the-smiling-pony. I might decide to design my own cutie marks once I figure out more about how these two grow up. For now they should work, though.