The current official terms do not cover her through the principal's payment alone. She should be included in the initial application and is subject to her own $15,000 DHS processing fee and $1 million government gift, with all terms rechecked before payment.
Her position is whatever the family terms state, and nothing more
The current official FAQ says that a spouse and unmarried children under twenty-one should be included in the principal's initial application. Each included relative is separately subject to a $15,000 nonrefundable DHS processing fee and a $1 million government gift after vetting; one applicant's gift therefore does not pay for the spouse. Successful family applicants receive the privileges of the Gold Card framework, which currently results in lawful permanent resident status through EB-1 or EB-2 subject to eligibility, admissibility and visa availability.
That status permits work and study but is permanent residence rather than citizenship. The couple must confirm the family terms and payment stages again on the official page before either spouse transfers money.