More than 31,000 people have signed a petition calling on Sussex Police to establish what happened to a woman whose death was deemed non-suspicious.
Blessing Olusegun, 21, was found dead on Bexhill seafront in September and a post-mortem concluded she had drowned.
Campaigners do not believe there has been a full investigation and a union also criticised the police response.
Sussex Police said there was no evidence of crime but the investigation remained "open and active".
According to the petition, the business student from south east London had been on a placement as a carer in Bexhill and was found dead with her shoes and phone near her.
It said: "The police are treating it as non-suspicious. Her mother Esther Abe is demanding to know why her beautiful daughter died."
A separate fundraising site, which has raised nearly £11,000, said Ms Olusegun went out for a walk at about 00:30 BST and sent text messages to her boyfriend and a close family friend asking them to "stay on the phone" but this did not happen.
Her last message came about an hour later.
It claimed police had not done enough, adding: "We want to find out how she died".
Sussex Police said Ms Olusegun's body was found on the beach near Galley Hill at 06:20 BST on 18 September.
The force said officers searched the area, interviewed people who spoke to Ms Olusegun, searched her room, examined her devices and phone records, reviewed CCTV and a pathologist carried out toxicology tests and a medical examination.
It said the post-mortem found no evidence of violence or injury, the death was being treated as unexplained but not suspicious, and an inquest would be held.
However, following recent vigils, a union claimed Ms Olusegun's death had not had the same response as Sarah Everard's, citing discrimination towards people of African heritage in public services.
Cheryl McLeod, Lewisham TUC president, said: "We mourn Sarah Everard... However, there is another death within our community, who like Sarah, was a woman who was walking alone."
Lewisham and Southwark TUC issued a statement which said: "We need justice for Blessing and her family. We need fairness and we need democratic accountability of the police and government."
Det Insp Pippa Nicklin said: "It has been reported that we have not properly investigated Blessing's death because of her ethnicity and we strongly refute these claims."
She said: "I have spoken with Blessing's mother and explained we remain absolutely committed to finding out the facts of what happened to Blessing. This is a very distressing time for her and we are keen to do everything we can."