Before heading to bed had one last glance at postings and reread:
"Johanna Dorothea WALLMANN aged 21 married Friedrich Willhelm HARTUNG aged 32 on 14th Dec 1848 at German Chapel Hindley St [Adelaide]
Ref = Ade 11/299"
Of interest as it might help with a connection, Heinrich named his daughter Louisa Dorothea.
Whilst I might be clutching at straws, it also might be a name connection back to Germany and help in linking siblings.

Elsie
there is this birth of interest
DANKEL Carl Wilhelm Otto 9/2/1852 ade 3/337
Father Johann Heinrich Christian DANKEL
Mother Wilhelmine Henriette Dorothea Magthalena WALLMANN
Digger - South Australian Deaths Registrations 1842 to 1915
Surname: DANKEL
Given Names: Carl Wilhelm Otto DANKEL died 9 weeks 19/4/1852 male aged 9weeks
Relative J H C DANKEL (F)
Relative 2 Minna DANKEL (M)
Book: 2 Page 132
Jenn