)[4] Helen's brother John Isaac Thornycroft began his shipbuilding career by constructing a steam launch at home in his late teens.

Helen, Hamo, Alyce, and Theresa were all trained in the Royal Academy schools starting in the 1860s, when the institution was only beginning to take female students.

The date and circumstances of Helen's entry are disputed; by one account, she applied in 1862, but was rejected by Sir Edwin Landseer because of her youth (she was 14 at the time).

[6] Helen started out as a sculptor like previous generations of her family; she exhibited a statue of Ophelia in the Royal Academy summer show of 1864.

His journals record an evening when the two of them walked home at 2:00 AM; Helen was up by 6:30 to go swimming, then worked at the Royal Academy schools until 2:00 PM.