Your sister is the most precious one in your life. That’s because if nobody has anger toward you, then you can’t practice the paramita of patience. It means you can’t practice patience, and if you miss that practice then you can’t achieve enlightenment. You have to practice the six paramitas and this means also the paramita of patience.
Your sister is giving you the opportunity to practice that, by arising anger toward you, so she is most kind among the sentient beings. She is helping you, giving you enlightenment, and as well as helping you practice patience now, in future lives you will have a good rebirth, a beautiful body and so forth.
When anger arises it destroys all our merits, which are the cause of happiness and success. Not only that, depending on whether she is a holy being or not, you will create the karma to be born in the lower realm for many eons. If she is a holy being, then it postpones your realizations for many eons. So there are three big shortcomings if you get angry toward her.
Therefore, think that she is like the guru, who by giving teachings makes the disciple achieve enlightenment. Similarly, by letting you practice patience, she is giving you enlightenment. She is so important, so precious.
And for her it’s not good at all, it’s worse. It’s what I told you—she creates negative karma by being angry toward you.
You can try reciting this mantra for her anger to go away. Recite the mantra just two or three times a day, just a few times. This is from the Buddha in the Kangyur.
The Exalted Zung Called “Thoroughly Pacifying Hatred”
If you pray to Arya Manjushri everyone will be loving and affectionate to you.
KÖN CHHOG SUM LA CHHAG TSHÄL LO
To the Three Rare Sublime Ones, I prostrate.
TADYATHA / DIRITISTHA / TASKARA VADDHOSI / MACALA MACALA SVAHA
Here, the Exalted Zung Called “Thoroughly Pacifying Hatred” is completed.
[See The Exalted Zung Called "Thoroughly Pacifying Hatred" for the latest version of this practice. You can also find links to a PDF of this practice in the FPMT Catalogue.]