On 24 February 1808 Nicolas-Gabriel married Adélaide-Marie Demante at Bourg La Reine. Adélaide-Marie was born on 9 July 1788 in Bourg La Reine to Thomas François Demante (1752-1823) and Marie Elisabeth Thérèse Durand. The Demante family had a home across the main street, the Rue Grande, from the Galois family and although Thomas François was 23 years older than Nicolas-Gabriel, the two had been close friends for many years. The Demante family also owned a house on the rue Jean de Beauvais in Paris. Thomas François had studied law at the Sorbonne and was a presiding judge. He was a passionate Latinist and had taught his daughter Adélaide-Marie philosophy, literature and other topics giving her a solid classical education. She was a very intelligent woman with a strong generous character. Nicolas-Gabriel and Adélaide-Marie Galois had three children, Nathalie Théodore Galois (born 27 September 1808), Évariste Galois (born 25 October 1811) and Alfred Galois (born 17 December 1814). Nathalie Théodore was named after her uncle Théodore Michel Galois who at the time of her birth was fighting in the French military campaigns. Nicolas-Gabriel registered the birth of his son Évariste on 26 October, the day after he was born, and chose the name Évariste since 26 October is the day of Saint Évariste, an early pope and Christian martyr.
On 26 February 1815, Napoleon escaped from exile on the island of Elba and began his journey to Paris to begin the famous 100 days. One of the results of Napoleon's return to power in France was the election of Nicolas-Gabriel Galois as mayor of Bourg La Reine, Paris. Always a popular figure, he continued to serve as mayor after the defeat of Napoleon at Waterloo. The restoration of the French monarchy should have led to the previous mayor being reinstated but he had been discredited and had left Bourg La Reine, so the popular Nicolas-Gabriel was able to retain his position despite his strong Republican views.
The three Galois children were educated by their mother Adélaide-Marie when they were young. In fact the eldest, Nathalie Théodore, never received any education other than from her mother. She married Benoît Chantelot in two ceremonies, the first on 28 January 1829 in Paris, and the second on 5 February at Bourg La Reine. The Galois family decided that the two boys were to be given a good school education and, when he was ten years old, the college at Reims was chosen for Évariste. He sat the entrance examination and his good performance led to him being awarded a grant. However, Évariste never went to this college because when the time arrived for him to begin his studies in Reims, his mother felt that the ten year old boy was too shy and gentle to leave home so he was given another two years at home to enjoy quiet family life. In fact he only began his schooling in 1823 when his parents decided that he really had to leave home and he was admitted as a boarder at the Lycée Louis-le-Grand in Paris.
For a shy boy who had enjoyed a peaceful upbringing in the family home, the Lycée Louis-le-Grand must have seemed a terrifying place to the young Évariste. Lessons were from 8 a.m. to midday, during which time the pupils were not allowed to talk except to answer their teacher. At midday they took a 45 minute lunch, again in total silence, followed by a short period when they were allowed to talk but not to run about. There were lessons again from 2 p.m. to 6 p.m. Following this there was a chapel service until dinner at 7.30, all in silence, after which, still in total silence, the boys got ready for bed which was at 8.30. Any talking, lack of attention, taking too large helpings at meal times and all sorts of other trivial misdemeanours were severely published with detention in one of the school's 12 cells. Typically punishment would last for four days during which time the boy was given long passages of Greek and Latin to translate. The headmaster of the Lycée Louis-le-Grand when Évariste arrived there was Nicolas Berthot, a mathematician who was a professor at the Faculty of Science and had been appointed as professor of descriptive geometry at the École Polytechnique in 1817. He was a staunch Royalist, a highly religious man who had refused to swear an oath to Napoleon, but was disliked by both Royalists and Republicans.
After the death of Thomas François Demante in 1823, his estate was settled and, in 1825, Évariste's mother received a one-third share of the house on the rue Jean de Beauvais. It was a house that the Galois family had spent much time in over the years and it had been a second home to the young Évariste. However, problems were already mounting for Nicolas-Gabriel Galois. Charles X had come to the throne of France in 1824 and he had worked to bring about an increase in the influence of the Church. A new young priest had been appointed in Bourg La Reine and he joined forces with others in the town who were intent on removing the Liberal Nicolas-Gabriel from his position as mayor. In an attempt to discredit the mayor, the priest forged the mayor's signature on a malicious poem directed against the mayor's relatives. This caused a scandal in Bourg La Reine and Nicolas-Gabriel, being a very sensitive man, was unable to cope with this. He went to the house on the rue Jean de Beauvais in Paris and on 2 July 1829 he committed suicide by asphyxiation by gas. He left one third of his estate to each of his three children.
After Nicolas-Gabriel's suicide, in October 1829 Évariste's mother moved from Bourg La Reine to take up residence in the house on at No 16 rue Jean de Beauvais in Paris. Évariste's uncle Théodore Michel Galois, who had been close to his nephew, died on 4 February 1831. Évariste's mother Adélaide-Marie had met Jean Christophe Loyer, a widower with two children from his marriage to Victoire Françoise Rouaux, living at No 6 rue Jean de Beauvais. Four months after Évariste's death his mother Adélaide-Marie married Victoire Françoise Rouaux on 8 October 1832. He is described on the marriage certificate as Maître d'Hôtel Garni à Elbeuf. After the marriage Adélaide-Marie moved from No 16 rue Jean de Beauvais to No 6 in the same street. However, this second marriage did not last long for Jean Christophe Loyer died on 21 August 1837.
Some time later, Adélaide-Marie moved in with her son Alfred Galois, a painter and artist, who was living at No 61 rue d'Enfer Saint Michel. He married Pauline Henriette Alexandrine Elodie Chantelot on 14 December 1841. They had two children, Elisabeth Julia Galois (6 April 1843 - 25 May 1855) and Évariste Galois (8 September 1848 - 4 April 1850) who had a much shorter life than his famous uncle whose name he had been given. Adélaide-Marie sold the Galois family home at No 20 Rue Grande, Bourg La Reine, in March 1851 to Pierre Ravon, who was at the time mayor of Bourg La Reine. She died on 1 August 1871 at Bourg La Reine.