You all had such brilliant answers that it was hard to choose! Here is the next round; I look forward to you continuing to wow me with your creativity 
Family 1
LN: Brisbane (PrincessShannon)
DW: [name_f]Abigail[/name_f] [name_f]Zenobia[/name_f] [name_f]Myrtle[/name_f] [Gasbeek] (namelover55)(kidpix21)
DH: [name_m]Aramis[/name_m] Feidhlim (SuzieKim)
DD: [name_f]Matilda[/name_f] [name_f]Saoirse[/name_f] (@namelover55)
DS: [name_m]Ruairidh[/name_m] [name_m]Xavier[/name_m] (@lolzabeth)
DD:
First name: contains the letters A, D and I
Middle name: contains the letters E, I, and R
Family 2
LN: [name_m]Thomas[/name_m] (lolaybimba)
DW: [name_f]Calla[/name_f] [name_u]Florence[/name_u] [Corbin-Hayes] (rosejuliet)(fivebutterflies)
DH: [name_m]Wilfred[/name_m] [name_u]John[/name_u] (pandasian)
DD: Enara [name_f]Primrose[/name_f] (@Novemberrain84)
DD:
First name: has an avian/bird-related meaning
Middle name: a flower that has petals in your favourite colour
Family 3
LN: [name_u]Heron[/name_u] (Indilee)
DP: [name_m]Sebastian[/name_m] [name_m]Wolfgang[/name_m] Krasimir (kidpix21)
DD: [name_f]Iseult[/name_f] [name_f]Ann[/name_f] Doha (namelover55)
Zebrafish: Chou (@EdgeOfTheMeadow)
[name_f]Cat[/name_f]: Metuka (@SuzieKim)
I couldn’t decide so they have two pets now!
DD:
First name: meaning related to warmth
First middle name: has an Arabic root
Second middle name: a world capital
Family 4
LN: Sunstone (Novemberrain84)
DW: [name_f]Serena[/name_f] [name_f]Charlotte[/name_f] [Hastings] (Luna-Skye)(EnglishRose3)
DP: [name_u]Sasha[/name_u] [name_u]October[/name_u] (Indilee)
DS: [name_u]Jasper[/name_u] [name_m]Aurelian[/name_m] (@lolaybimba)
DD:
First name: ends in a schwa sound (like the a in about)
Middle name: has a Latin root
Family 5
LN: Vickers (EdgeOfTheMeadow)
DW: [name_f]Mariposa[/name_f] [name_f]Ayala[/name_f] [Greenvale Navarro] (SuzieKim)(lolzabeth)
DP: [name_f]Persephone[/name_f] [name_f]Maeve[/name_f] (Luna-Skye)
DS: [name_u]Harry[/name_u] [name_m]Porfirio[/name_m] (@Indilee)
DS: [name_u]Ridge[/name_u] Espiridión (@VEL)
I couldn’t decide so they have surprise twins!
DS:
First name: a name you think sounds sporty/athletic
Middle name: an underused or rare Spanish name
Family 6
LN: [name_u]Beck[/name_u] (BeccaRhubarb)
DW: [name_f]Cordelia[/name_f] [name_f]Maren[/name_f] [Brewster-Bell] (kidpix21)(EdgeOfTheMeadow)
exDH: [name_m]Theodore[/name_m] [name_u]Michael[/name_u] [name_u]Beck[/name_u] (PrincessShannon)
DH2: [name_u]Niall[/name_u] [name_u]George[/name_u] [name_m]Way[/name_m] (@BeccaRhubarb)(@lolaybimba)
DD: [name_u]Havilah[/name_u] [name_f]Isabeau[/name_f] [name_u]Beck[/name_u] (VEL)
DD: [name_f]Gaia[/name_f] [name_f]Evangelista[/name_f] [name_u]Beck[/name_u] (namelover55)
DSS: [name_u]Kayden[/name_u] [name_u]John[/name_u] [name_m]Way[/name_m] (@namelover55)
DSS: [name_u]Leo[/name_u] [name_u]Jasper[/name_u] [name_m]Way[/name_m] (@Indilee)
DS:
First name: bridges the two name styles of [name_f]Gaia[/name_f] and [name_u]Havilah[/name_u] vs [name_u]Kayden[/name_u] and [name_u]Leo[/name_u]
Middle name: a name that is uncommon but recognisable