May be I don't understand you completely. You are looking for Frederika Denneboom. Result: the person you refers has the name Frederika Tas. There is no son but a daughter.
Next question. You wrote:
Besides Frederika mentioned, I also found (possible sisters and brothers?)
Marianna Denneboom 211/6/1908 A'dam-6/3/1944 Auschwitz married with Philip Visschoonmaker 27/5/1911 A'dam-31/7/1944 ? and so on
Answer no sisters and brothers of this Frederika. By sending you the names of the children of Benjamin and Evy :
For Marianna year of birth differs,
Meyer Denneboom 26/6/1905 A'dam-22/10/1943 Auschwitz
Vrouwtje Denneboolm buried Zeeburg 24/12/1899 C 12 44, daughtger of Benjamin DenneboomNn
NN Denneboom maried with Bertje Gobetz buried Diemen 12/6/1930 B16 75
NN Denneboom married with Rebecca Riff buried Diemen 1/6/1931 B 24 18
They are not children of this benjamin Denneboom.
I also put a link to the Amsterdam archive in my message. It will be usefull for further investigations. And you can donwload the archiefkaart.
For people outside of Amsterdam and died after 1939 you can order In The Hague a so-called persoonskaart with information of birth, death, marriage and parents
http://194.171.109.12/page/280/research
If you like to have the few cards I already have downloaded please contact me.
Kind regards