What would be her best career pursuit?

Sun and Mars are in mutual reception, too. Sun square moon is a hard placement. Mercury is her ruling planet, where's it? Trines can make people lazy and take things for granted but it's amazing how many personal planets she has that are either in dignity or exaltation. A planet's energies work best in dignity or exaltation and she has her sun, moon, venus, mars (by mutual reception) and jupiter all working very well in the signs they're in.

Possibly entertainment, for career. The hospitality industry. Maybe even politics. Depends on which houses these planets are in but she'll lead a charmed life.

EDIT: I'm thinking her best bet would be that of a local TV newsperson. There's a lot of energy in fire and mercury needs constant change and stimulation and the 3rd house mars. If she's attractive, she should make quite an impression and may go far as a reporter.

She should have many good qualities

Sun in Aries (strong)

Jupiter in Sag (own sign)

Venus in MC

She can follow any administrative Job

Go for anything that keeps her around people, communicating and socializing a lot.

Truism

Hospitality

Marketing

International Relationships