Anna Ermakova, Becker s daughter conceived out-of-wedlock on the stairwell of the Nobu restaurant in Park Lane, posted the message of thanks on Instagram over the weekend.
Anna Ermakova said she was concerned about the welfare of her younger brother Amadeus without his father and said she had written to the court before her father was jailed yesterday.
The 54-year-old former world number one tennis player was declared bankrupt in June 2017, owing creditors almost £50million over an unpaid loan of more than £3million on his estate in Mallorca.
Christian Schommers, who wrote a biography on tennis legend Boris Becker, said: Will he survive mentally, being in prison for a year and three months? It s really, really bad!
The prospect of jail appeared to weigh heavy on the former tennis star, who looked downcast as he walked through London wearing a grey hoodie, brown coat and a baseball cap.