Note that in the records I have seen she occurs as follows
In her marriage record to Mart Walter her name is Prandmann
For Alexander's, Liisa's and Anna's births she is Trantmann
For Marie's and Koidula's births she is Brandmann
and for Melanie's birth it is back to Trantmann, so we have one Prandmann, two Brandmann and four Trantmann.
In all records where her origin is mentioned (Personaalraamatud and marriage) it is Takerorth or Tahkuranna.
In all the records available for Tahkuranna/Takerorth there are no Trantmanns ever mentioned. However, there is a family of Brandmanns and there is a Johan Brandmann who is the right age to be her father. Regrettably I can find no record of his marrying a Lisa or marrying at all for that matter. In the February 4,1858 (Muhho, Takerort) Revision he does not appear to be married yet but is aged 25 so may have been about to marry. I have convinced myself that this is Melanie's father as this Johan has a mother also named Melania in that Revision listing, and I feel that is a coincidence too far if he is not Melanie's father..