From him, from Muhammad ibn Isma'il, who said:
I asked al-Ridha عليه السلام about a man engaging in intimacy with a woman without penetration, and the woman ejaculates. Does she need to perform ghusl? Imam عليه السلام replied: Yes.
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 131