Is it permissible to use the Photoshop program that my sister bought, and is her purchase of it sufficient for me to download and use it on my device without needing to buy my own?

It is not permissible to copy programs whose owners prohibit copying them except with their permission, based on the Prophet's (peace be upon him) sayings: "Muslims are bound by their conditions," and "The wealth of a Muslim person is not lawful unless given with the full consent of his soul," and "Whoever is first to a permissible thing has a greater right to it." The Islamic Fiqh Academy has affirmed that copyrights, invention rights, and patent rights are special rights belonging to their owners, which are legally recognized and must not be infringed upon. Consequently, it is not permissible to infringe upon programs whose owners prohibit copying them, but it is permissible to benefit from the original copy that a person has purchased.