Kinyume spent the first years of her education being homeschooled by Zecora, before she and Daring decided that Kinyume needed to socialize more with foals her age, and enrolled her in Ponyville elementary. She was a bit nervous of not making any friends, due to how she was part zebra, didn't have her mark yet, and just wasn't sure how this "interacting" was supposed to go.
So she was actually relieved to realize she recognized some of the other foals in her class as the kids she was sometimes forced to play with when her mother's friends visited and brought their families along. She didn't know them very well, but they had seemed nice.
Disco, on the other hoof, was absolutely ecstatic. Not only was there a new future friend in his class, but this one was half-pony just like him. Before even speaking to her, he was planning what their best-friends bracelets should look like.
Kinyume, for her part, found him suprisingly easy to interact with. Sure, he was a bit annoying and dominated all their interactions, but she hadn't really had a friend before, and here was one who was willing to do all the work of becoming friends without much input from her. So when she was invited over after school, she agreed without much hesitation.
Too late did she realise her mistake.
——
The first meeting of Kinyume and Disco, and the start of a beautiful friendship. Well, sort-of a first meeting, they've actually met when they were much younger and Pinkie brought him along to Zecora, but they were too young to remember that. They didn't get along at all, and ended the play-date with Kinyume biting his ear and Disco kicking her into a wall. Pinkie had wanted them to become friends, much for the same reasons Disco wants to be friends now, hoping that they could relate to each other and have someone to talk to. But when they hit it off so badly, she paniced a bit and went to the extreme of… not keeping them apart, but not putting them into situations where they had to interact. A bit of an overreaction to the first meeting etween toddlers, but she was very concerned with being a good mom, and decided to err at the side of caution with protecting her baby.
So when Disco introduces Kinyume as his "newest best friend forever", she's through the roof, giddy that they had set aside their fight (i.e. not remembering it) and were able to get along. A bit too excited though, she'll have to work to make Kinyume not afraid of her in the future.