The investiture of Mar Lleixà was achieved thanks to the government agreement between Esquerra Republicana and Movem-PSC, adding the votes of the CUP. In total, she secured eleven votes in favor, surpassing the ten votes of the opposition leader, Meritxell Roigé. This makes her the first Republican mayor of the city since 1939.

Her professional career is extensive. Lleixà studied Nursing and Psychology, earning a doctorate in 2008. She currently works at the Hospital Universitari de Tortosa Verge de la Cinta (HUTVC) and was a nursing professor at the Terres de l'Ebre Campus of the Universitat Rovira i Virgili for two decades.

Furthermore, Lleixà was the first woman and nurse to head the Territorial Health Directorate in the Terres de l'Ebre, a position she held during the covid-19 pandemic. In the educational field, she chaired the AMPA (Parents' Association) of the Institut Joaquim Bau, where she promoted the change of the center's name to Dertosa in 2018.

Regarding her personal side, the mayor currently resides in Remolins, although she previously lived in Temple and Ferreries. Among her hobbies is cooking, being passionate about traditional dishes, stews, and rice dishes. She is also known for regularly buying local products at the Tortosa Market on Saturdays.

Finally, Mar Lleixà also has a strong social commitment, as she participates annually as a volunteer in the Gran Recapte (Great Food Collection) and has collaborated with Càritas, in addition to being a blood donor, highlighting her solidarity.