Cruz developed her career practicing law in La Paz and El Alto, during which time she became an active member and advisor to various human rights NGOs.

Though intended to serve as acting ombudsman for just ninety days, procedural delays and a year-long political crisis led Cruz's tenure to drag on, even exceeding the expiration of Tezanos Pinto's original term.

[2][3] Around this time, she became a member of the Permanent Assembly of Human Rights before serving as a legal advisor for the Association of Relatives of Disappeared Detainees and Martyrs for National Freedom (ASOFAM) from 2007 to 2010.

[4] In the ensuing two years, Cruz held minor legal positions in the ministries of government and justice before returning to the Ombudsman's Office as head of conflict prevention and attention.

[1][3] Cruz's tenure as deputy ombudsman coincided with the sudden resignation of incumbent David Tezanos Pinto, who was forced to step down mid-term to deal with a domestic violence suit filed by his then-wife.

By the end of her expected term in April, the MAS opted not to replace Cruz with a new acting authority, justifying that the ninety-day mandate was merely "customary" and not enshrined by law.

[8] Throughout Cruz's extended tenure, her administration routinely faced criticism from the political opposition for her alleged partisan bias in favor of the ruling party, with opponents pointing to her participation in pro-MAS electoral rallies and other events as evidence of this claim.

The new government asserted that Cruz's term had expired upon the completion of her ninety-day mandate in April and, therefore, that she was illegally exercising the position of ombudsman, for which all official acts she had since carried out were declared null and void.

[13] Though the MAS-majority Mixed Legislative Commission overseeing the election process initially qualified her to move to the second phase,[14] Cruz's candidacy was challenged by the opposition on the grounds that the Constitution prohibits any former ombudsman from running again regardless of whether or not they performed their functions in an acting capacity.

[18] Ultimately, however, the ruling party opted to extend Cruz's mandate as ombudsman, relying on an interpretation of the body's regulations that allowed for an acting authority to remain in office until the appointment of a new official.