I scrounged up some interesting information on Eugenie from her mother's biography. In childhood, both her father and her mother favored her brother Peter. However, this worked out strangely:
"Marie was proud of having given birth to a boy. Despite her principles of fairness in devoting equal time to the children in their games and education, she was unaware of the degree to which she favored the boy. But she was even more unaware that her love for Peter was more crippling than enabling for him."
Eugenie studied Chinese under the direction of Soulie de Morant, a distinguished sinologist. She attended public schools, as did Peter. They called their great uncle Valdemar "Papa Two" because they saw him so frequently. Marie Bonaparte wanted to stimulate her children's intellect and imagination, but their governess Croisy was highly conventional and both children became confused between two sets of values. From reading the biography, I gathered that both Marie and George loved the children, but maintained a distance from them. While Eugenie was going through puberty, Marie was busy being psychoanalysed by Freud in Vienna.
In November of 1926, when Eugenie was 16, she became very ill and Marie rushed to Paris to be with her. Dr. Talamon warned the parents that she probably had tuberculosis.
"George remarked that doctors were pessimists and went on to state that he was glad it was not Peter." 
What a hideous thing to say!!!
On Dec. 10th tuberculosis was confirmed and Eugenie spent the next eight years in ill health. She suffered initially from pulmonary tuberculosis. "She accepted her illness with good grace and much consideration towards others," writes Celia Bertin. Marie began to spend more time with her. "She wrote Freud that only Eugenie understood her, a sentence she was often to repeat."
During her illness, Eugenie lived in her own house and spent her time reading and playing with her pet chow-chows.
Although it's terrible Eugenie's health restricted so many years of her youth, she survived tuberculosis which killed so many people in the past.
