Also just because she died in the workhouse it does not mean she was buried by them. It was not uncommon for relatives to take the body away for a private burial - this would be noted in the discharge register if the case. As the death is in 1906 you should be able to look up the record or ask the archives to do a search (probably paid)
sorry the death was in 1911, i recall there being another death of the same name which i checked out but it was not her, i think this may be your 1906 death.
with regard to the lewes record office yes but it is closed while they move premises i believe.
I know where that main cemetery is so i might be able to ask there or have a look around one day.
I know one of her previous census records said midwife - sick, and then the next she was in the workhouse.
cheers