It seems our mails crossed each other.
I suggest you mail Rotterdam first and then please let me know if they could help,
It depends on the archiv if they give you information for free (if it's f.e. just about one thing, f.e if you ask if it's right that she died in R'dam), when there a higher costs I could try for you to ask someone to go there (free)
The family card (till 1939) is online, I can send you it, or you can see it yourself, go tohttp://rotterdam.digitalestamboom.nl/%28sq5v4d454g0wosmg5204...
the ''population register' and fill in the name,
maybe this direct link to the card works:http://rotterdam.digitalestamboom.nl/detailx.aspx?p=24359211...
click on ''view the scan'' and you see the forside of the card,
click next to the ''point'' you see above and you see the back of the card.
This is from the Population register, that goes till 1939/1940
After that in NL you have the ''Persoonskaart'' (Personal Card),
the kind of card I spoke about in order to find the death of F.H. M Schrijver.