Summer Plans PV CASH

It was only the second day of the holidays, but Lucia was already enjoying watching her younger sister attempt to argue with Ebony, their mother.
"Ebony." Briar probably thought she sounded calm and willing to compromise. In reality, though, she and Ebony were just as stubborn as each other and were at an impasse here. "It's only a week. Me and Faith are really looking forward to it. You have to let me go!"
Ebony gave a look-how-much-I'm-suffering-type sigh. "Briar. A week is about five days too many. You can go for a day if you like, or even have a sleepover, but not a week."
"But- but if I only go for a sleepover," Briar cried, "I'll miss the concert!"
This was news to Lucia. "There's a concert? Can I go?"
Everyone else in the room (except Willow, who was calmly staying out of it by reading a book in the corner) turned on Lucia. "No!" they both said in unison. Oops. Maybe Lucia shouldn't have said anything. "Don't you have your own friends?" Briar added snobbishly.
Lucia blinked. Sure, she had her own friends, but she hadn't made any plans for the summer with them. Should she have done? Before she could reply, Ebony jumped in. Apparently, having Lucia to gang up on ended the hostility between the two. "What about the Ironwoods' child? Cassandra?"
"Cash," Lucia corrected. "And, um, I guess..." She wasn't entirely sure why her mother's mind had jumped straight to Cash. Maybe it was because they lived in Oxford too so they wouldn't have to waste any Floo Powder.
"That settles it, then." What? "Briar will write to Faith and say she can stay for one night only. Lucia will write to Cash and suggest that they meet up. Suggest their house before ours, dear."
And, apparently, that was that.

Dear Cash,
How are you finding your summer break? Yes, I know we've only had one day of it so far, but it was a nice day, so that's good.
My youngest sister - Willow; do you remember her? - has practically adopted my rock friend (you know, the one that has been following me around for a few months, it's quite small so you might not have seen it).
Since we live so close to each other (by Hogwarts standards anyway - I guess that's what happens with boarding schools, although people don't seem to have distance problems in books), what do you think about meeting up at some point? I don't think I'm going to summer camp so I'm basically free for the whole two months. I could go to your house, or you could come to mine (you know where it is now, after all), or we could just go to a park or go shopping or something.
It will be funny interesting to see how soon you get this owl. Since we live so close to each other it shouldn't take as long for us to owl each other as it generally does when you're sending owls over long distances. Apparently, Muggles have a method of communicating that happens instantaneously, but I find that hard to believe. No animal or vehicle can move that quickly, and it's not like paper can Apparate, or use the Floo network! (Actually, what would happen if you put paper in the Floo network? Would it just burn?)
Anyway, it's nearly time for tea so I'll sign off.
Hope to hear from you soon,
Lucia