One of the Tromp daughters faces charges of stealing a car as the fallout continues from a bizarre Victorian family road trip that left two of them in hospital with trauma.
Ella Tromp, 22, was charged with theft of motor vehicle and possessing proceeds of crime on August 30 in Victoria, and is due to appear in the Ringwood Magistrates Court on April 19 next year, police said on Monday.
She and her brother Mitchell gave a press conference at their Silvan home on Sunday, when they told reporters they were still confused about why their family of five got in a car a week ago, sparking a missing persons search on Tuesday.
The pair drove off to NSW last Monday with their father Mark Tromp, his wife Jacoba and their sister Riana.
By Tuesday, all three adult children abandoned the trip and authorities were called in to investigate, finding the Silvan home unlocked and phones and credit cards left behind.
Mitchell, who made his own way to Melbourne from Bathurst, told reporters on Sunday that getting out last Tuesday "was the best idea at the time".
Riana and Ella left their parents near Jenolan Caves and headed to Goulburn.
There the sisters split up.
Riana was found "catatonic" in the back of a ute and taken to hospital, while Ella returned to Melbourne, and was later charged by police with alleged car theft.
Mrs Tromp was found on Thursday in Yass Hospital in an emotionally poor state as police continued to search for her husband.
He was found safe in Wangaratta on Saturday.
Mrs Tromp has since been transferred to Goulburn Hospital. She and Riana, 29, were still being treated there on Monday.
Police say on Monday they also charged a 29-year-old Silvan woman with theft of motor vehicle on 30 August in NSW. The charges have since been dismissed under Section 33 of the Mental Health Act of New South Wales.
On Sunday in Silvan, Mitchell and Ella were unable to explain what happened on the family trip.
Mitchell said "possible things" might have led to the panicked trip.
But he wouldn't comment on whether a family dispute or mental health issues were the trigger.
Police continue to investigate.
