In same way how they used to lived happily in Golok Dham, don't you know that Mata Radha and Mata Rukmini are soul sisters, they enjoy each other's company very much. Many scriptures praise their sisterly bond.
Goloka is the Parama dham of lord Krishna,
where he always resides with Mata Rukmini and Mata Radha.
अथ श्रीकृष्णदेवाय राधया विरजादिभिः ।
रुक्मिण्या चाभियुक्ताय गोलोकाऽऽवासकारिणे ॥ ३९ ॥Obeisance to lord Sri Krishna who resides in Goloka with Radha, Viraja and Rukmini.
~Lakshmi Narayana samhita, krita-yuga khanda, chapter 160
In Dwapar Yuga when Lord Shri Krishna incarnated on earth to relieve the burden of the earth, Mata Rukmini and Mata Radha were also incarnated with him, because every leela of Lord Shri Krishna is incomplete without our beloved mothers Shrimati Radha Rani and Shrimati Rukmini Mata. Along with them, Prabhu Sankarshan, Pradyumna and Aniruddha also take incarnation in the Yadu clan.
Lord Krsna said: O Brāhmaṇa, I, who am such accompanied by Rādhā and Lakṣmī always stay in this imperishable residence (Goloka) along with my dependents.
32-33. When the junction of Dvāpara and Kali comes to a close, for the sake of annihilation of Asuras who become burden to the earth, and for protecting righteous people, I, Kṛṣṇa, called Vāsudeva, will be born of Vasudeva and Devakī in the city of Mathurā. Similarly Saṅkarṣaṇa alias Balarāma, Pradyumna and Aniruddha (i.e. all the Vyūhas of the Pāñcarātras) will be born in the family of Yadu.
34. Rādhā will be the daughter of the cowherd Vṛṣabhānu and I shall sport with her in Vṛndāvana, O Lotus-born One (Brahmā).
35. Lakṣmī will be born as the daughter of Bhīṣmaka by name Rukmiṇī. After defeating kings in a battle, I shall marry her.
~Skanda Mahapuran, Vasudeva mahatmya, chapter 18
This is not the first time that Mata Radha met Mata Rukmini and Pradyumna, they all reside in Goloka. And Pradyumna ji is the beloved son of Lord Krishna and Mata Rukmini, that means he is the beloved son of Mata Radha too.
JAY SHRI RADHA KRISHNA 🙏
JAY SHRI RUKMINI SHYAM 🙏