The collision happened on Friday afternoon in Coromandel, on State Highway 25 near the turnoff to popular holiday spots Hot Water Beach and Hahei.
Waikato district road policing manager Inspector Freda Grace said a decision on whether charge would be laid was yet to be made.
"We are still carrying out our investigation into what's occurred," Ms Grace said.
Decisions on charges would be discussed, she said.
Mrs Derrick's daughter Amy McPake said on Facebook today a service would be held for her mother on Friday at Fountain Funerals in Papakura.
AA spokesman Mike Noon said the crashes over the weekend were tragedies for the families involved, for whom Queen's Birthday weekend would now always be ruined.
The holiday road toll stands at five.
More work needed to be done to analyse the crashes tourists were having here versus the crashes local drivers were having, he said, to find out of there were specific problems in foreigners understanding New Zealand roads.
"There have been tragically a number of crashes involving tourists recently. This weekend what we're seeing is unfortunately two of the major crashes have involved foreign drivers.
"Have we just had an unfortunate spate involving those drivers or do we actually need to increase the information available to those drivers? We've had a pretty tragic run over the past few days."
He said it would be too difficult to test all tourists into the country before they drove.