Dear Diane,
The GenLias database (index to the civil registry, see
http://www-lias.rad.archief.nl/genlias/ara/logon?cid=-1) does contain information about the late 18th century, although it was started in 1811. I found:
(Gasselte, 24 May 1846) death of Annechien Berends Bos, born in Anloo 20 Dec 1798, dr. of Berend Jelkes Bos and Grietje Folma. She died 23 May 1846 and was the wife of Reint Roossien [I could have known ;-) ]
Other children I did not find, their death were not in GenLias either. This could mean that they moved to Groningen, there was a lot of "traffic" between Gasselte (Drenthe) and Wildervank/Onstwedde (Groningen), e.g., and of Groningen there's not much in the database yet.
Good luck!
Lars Roobol