Can I just say that I find the names of [name_m]Roald[/name_m] Dahl’s kids fantastic, especially as siblings (though some are quite close).
[name_f]Olivia[/name_f] Twenty Dahl (*1955 ”1962)
[name_f]Tessa[/name_f] Dahl (1957)
[name_u]Theo[/name_u] [name_m]Matthew[/name_m] [name_m]Roald[/name_m] Dahl (1960)
[name_f]Ophelia[/name_f] [name_f]Magdalena[/name_f] Dahl (1964)
[name_f]Lucy[/name_f] [name_u]Neal[/name_u] Dahl (1965)
Wdyt?
I like the names too, I think there’s an undeniable British feel about them (since R. Dahl is British…) and the sibset flows quite easily!
I found that [name_f]Tessa[/name_f]'s first name is actually [name_f]Chantal[/name_f]:
“[name_f]Olivia[/name_f] Twenty (1955–1962)
[name_f]Chantal[/name_f] [name_f]Tessa[/name_f] [name_f]Sophia[/name_f] (b. 1957)
[name_u]Theo[/name_u] [name_m]Matthew[/name_m] (b. 1960); [name_f]Ophelia[/name_f] [name_f]Magdalena[/name_f] (b. 1964)
[name_f]Lucy[/name_f] [name_u]Neal[/name_u] (b. 1965)”
And his granddaughter [name_f]Sophie[/name_f] Dahl (Holloway) is [name_f]Tessa[/name_f]'s daughter, so maybe a variation of her 3rd name, [name_f]Sophia[/name_f] 
I think they gave some thought to their name choices!
I have seriously been contemplating using [name_u]Neil[/name_u] as a middle for a daughter. This just assured me that it’s okay, I also love [name_u]Neal[/name_u] (it just looks slightly more feminine).
[name_f]Olivia[/name_f] Twenty is my fav combo.
I saw [name_f]Chantal[/name_f] [name_f]Sophia[/name_f] too, but as she went by [name_f]Tessa[/name_f] (which I like much better) I included this one.
You might me right about [name_f]Sophie[/name_f], it looks very much like she was named after her mother!
[name_m]Roald[/name_m] Dahl lived in [name_m]Wales[/name_m] [then went to school in [name_f]England[/name_f] but his parents were Norwegian, he spent many summer holidays visiting there and all the family could speak the language well. I like his [Norwegian sounding] siblings names:
Alfhild
[name_f]Astri[/name_f] [died age 7 of appendicitis]
[name_f]Asta[/name_f]
[name_f]Else[/name_f]
Of course, [name_f]Lucy[/name_f]'s middle name [name_u]Neal[/name_u] is from her mother, the fabulous [name_f]Patricia[/name_f] [name_u]Neal[/name_u].
[name_f]Sophie[/name_f] and her variants go even further back in the Dahl family, as his mother was named [name_f]Sofie[/name_f] [name_f]Magdalene[/name_f].
And there’s some very [name_u]Berry[/name_u] names in recent branches of the Dahl family tree too; [name_f]Sophie[/name_f]'s half-siblings are named [name_f]Clover[/name_f], [name_m]Luke[/name_m] and [name_m]Ned[/name_m], and her daughters are named [name_f]Lyra[/name_f] and [name_f]Margot[/name_f].