Amrit Magar from Edgware was convicted at Bromley Magistrates' Court on Friday and will be sentenced at a later date.
Magar was captured on door camera footage at the 19-year-old player's south London home, where she lives with her parents, leaving notes and cards.
In a statement to the court, reported by the Daily Mail, Raducanu said she was now fearful of going out alone.
"Since all this has happened, I have felt creeped out. I feel very apprehensive if I go out, especially if I am on my own," she told police in a statement.
"Because of this I feel like my freedom has been taken away from me. I am constantly looking over my shoulder. I feel on edge and worried this could happen again. I don't feel safe in my own home which is where I should feel safest."
Magar visited Raducanu's home a number of times during December last year.
On one occasion, the former Amazon delivery driver left a hand-drawn map to show the tennis player he had walked 23 miles from his house in north-west London to reach her.
He also left her a note which read "you deserve love".
Raducanu, the reigning US Open champion, was named BBC Sport Personality of the Year in December.