Do you consider my colleague a Muslim after she has recited the Two Testimonies of Faith, and how should I interact with her, knowing that she is afraid of her husband and only repeats the Two Testimonies of Faith as a form of remembrance?

A woman becomes Muslim simply by uttering the Two Testimonies (Shahadatayn). It is then incumbent upon her to submit to the laws of Islam and act in accordance with the Two Testimonies. If she does not act accordingly, she must be invited, taught, and dealt with kindly until she fulfills God's obligations. She must also contact the nearest Islamic center or reliable websites to learn what is necessary for her Islam to be valid.