I think on the population record a 7th sibling is missing.
An other Geertje was born in 1872 and died also that year.
I'm using this site , were you can check all the dates yourself :
https://www.wiewaswie.nl/en/search/advanced-search/The Dutch death records never mention the cause of death.
After you find the record date ( on the birth- and death record not always the same as the date of birth or death ! ) on the side mentioned above you go to this site :
http://zoekakten.nl/There you go to ZH ( = the province Zuid-Holland ) - Melissant- indexen
(geboorten = births , overlijden = deaths and huwelijken = marriages )
Good luck,
Jan