Yulia Skripal, poisoned daughter of Russian ex-spy Sergei, has rejected assistance from the Russian embassy “at the moment”.
The 33-year-old, who was discharged from hospital on Monday, said her father is “still seriously ill”.
In a statement issued through police, she said she was not yet strong enough to give a full media interview but “no-one speaks for me, or for my father”.
The Skripals were found slumped on a park bench in Salisbury on 4 March.
Ms Skripal and her 66-year-old father, who remains at Salisbury District Hospital, were exposed to the toxic nerve agent Novichok.
In her statement she said she found herself in “a totally different life than the ordinary one I left just over a month ago”.
Ms Skripal, who has been taken to a secure location, added: “I have specially trained officers available to me, who are helping to take care of me and to explain the investigative processes that are being undertaken.”
After Ms Skripal’s release from hospital, the Russian embassy said: “We need urgent proof that what is being done to her is done on her own free will.”
In her latest statement, Ms Skripal said: “I have access to friends and family, and I have been made aware of my specific contacts at the Russian embassy who have kindly offered me their assistance in any way they can.
“At the moment I do not wish to avail myself of their services, but, if I change my mind I know how to contact them.”
The UK government says Russia was behind the poisoning, which has led to a diplomatic crisis between Moscow and the West.
The Russian government has denied any involvement and accused the British of inventing a “fake story”.
More than 20 countries are expelling Russian envoys in solidarity with the UK.
Tests on the nerve agent used on the Skripals have been conducted by the Organisation for the Prohibition of Chemical Weapons (OPCW).
A report from the OPCW has been received by the Cabinet Office and an executive summary will be published on Thursday.
While Yulia and Sergei were both being treated in hospital, her cousin Viktoria Skripal, who lives in Russia, gave interviews to Russian news agencies and international outlets.
Following Ms Skripal’s discharge from Salisbury District Hospital on Monday, her cousin told Russian news agency Interfax that Ms Skripal planned to ask for political asylum – although she did not know in which country.
But in her most recent statement, Ms Skripal clarified that Viktoria’s “opinions and assertions are not mine and they are not my father’s”.
She said: “I am not yet strong enough to give a full interview to the media, as I one day hope to do. Until that time, I want to stress that no one speaks for me, or for my father, but ourselves.
“I thank my cousin Viktoria for her concern for us, but ask that she does not visit me or try to contact me for the time being.”