Combining the names:
[name_f]Thea[/name_f] (From [name_f]Dorothee[/name_f] and using letters of [name_f]Martha[/name_f] and Hertha)
[name_m]Edmond[/name_m] (combining the sounds of [name_f]Emma[/name_f], [name_f]Dorothee[/name_f] and Harmon)
[name_m]Jem[/name_m] / [name_f]Jemma[/name_f] (combining the middle initials J E M - and -a ending of [name_f]Emma[/name_f], [name_f]Martha[/name_f] and Hertha)
[name_m]Cru[/name_m] / [name_m]Crue[/name_m] / [name_m]Crew[/name_m] (combining [name_f]Christine[/name_f] and Hugh)
[name_f]Marnie[/name_f] / [name_f]Marnee[/name_f] (combining [name_m]Harmon[/name_m] and [name_f]Martha[/name_f] and Dorothee)
[name_f]Marine[/name_f] (Martha and Christine)
[name_m]Hudson[/name_m] (Hugh, [name_m]Harmon[/name_m], Dorothee)
[name_f]Jodie[/name_f] (Julia and Dorothee)
[name_f]Heather[/name_f] (Hugh, [name_m]Harmon[/name_m], Hertha)
[name_f]Journey[/name_f] (combining sounds of [name_f]Julia[/name_f], [name_f]Erna[/name_f] and Dorothee)
[name_f]Carmen[/name_f] (Harmon and Christine)
You could also just do it by initials, since you’ve got four initials to honour?
So, like:
[name_f]Ada[/name_f] [name_f]Charlotte[/name_f] [name_f]Hope[/name_f] and [name_f]Nora[/name_f] [name_f]Madeline[/name_f] [name_f]Eve[/name_f]
[name_m]Aaron[/name_m] [name_m]Hugo[/name_m] [name_m]Mack[/name_m] and [name_m]Jasper[/name_m] [name_m]Caleb[/name_m] [name_m]Elias[/name_m]
[name_f]Chloe[/name_f] [name_f]Matilda[/name_f] [name_f]Elsie[/name_f] and [name_m]Joshua[/name_m] [name_m]Henry[/name_m] [name_m]Clark[/name_m]
[name_f]Leonor[/name_f] [name_f]Hollie[/name_f] [name_f]Elisabeth[/name_f] and [name_m]Jasper[/name_m] [name_m]Maxwell[/name_m] [name_m]Charles[/name_m]