The practice of the 21 Praises to Tara can be done in this way, where the practice becomes specific according to the problems and obstacles being faced by a person or people. If that is a disease, it can have that focus. If somebody is trying to avoid prison, it can have that focus. Every problem or fear can be approached with this practice.
Please perform the 21 Praises to Tara at the Dharma center four times in a week. As you are not doing the full sadhana, you should start with refuge and bodhicitta, then the four immeasurable thoughts, then generate bodhicitta, followed by the Seven Limbs and short mandala offering.
When you do the 21 Praises to Tara, you can recite each of the Tara mantras, with a strong prayer to each Tara for Joanne to recover from her illness.
When it comes to White Tara, recite the White Tara mantra 30 times, sending white purifying light to Joanne.
When it comes to Tara Destroying all Obstacles, recite this mantra 70 times, visualizing Tara sending light destroying all obstacles, diseases, spirit harm, and negative karma. Recite the mantra with this visualization.
When it comes to the Tara giving long life, recite her mantra 50 times, sending light pacifying all life obstacles and untimely death.
When it comes to the Tara whose purpose is to prevent harm, especially black magic, recite her mantra 50 times.
You can repeat this up to three times. This means, for the first one to three recitations of the 21 Taras, you can elaborate as I have explained here. After doing one to three recitations of the 21 Taras this way, then you can continue doing the 21 Praises in the normal way.
At the end, read the benefits of reciting Tara praises and then recite the dedication prayers. There are seven important dedications, like the King of Prayers, that you can read. You can choose.