The two sons of Vallabhacarya were Gopinatha and Viththalesvara. When Sri Caitanya Mahaprabhu visited Prayaga in the year 1434 or 1435 Sakabda Era (A.D. 1512 or 1513), Viththalesvara was not yet born. In this regard, one should see Madhya-lila 18.47

Expressions researched:
"The two sons of Vallabhācārya were Gopīnātha and Viṭhṭhaleśvara. When Śrī Caitanya Mahāprabhu visited Prayāga in the year 1434 or 1435 Śakābda Era (A.D. 1512 or 1513), Viṭhṭhaleśvara was not yet born. In this regard, one should see Madhya-līlā 18.47"

Sri Caitanya-caritamrta

CC Madhya-lila

The two sons of Vallabhācārya were Gopīnātha and Viṭhṭhaleśvara. When Śrī Caitanya Mahāprabhu visited Prayāga in the year 1434 or 1435 Śakābda Era (A.D. 1512 or 1513), Viṭhṭhaleśvara was not yet born. In this regard, one should see Madhya-līlā 18.47.

CC Madhya 19.108, Translation and Purport

Vallabha Bhaṭṭācārya was struck with wonder to see Śrī Caitanya Mahāprabhu and Raghupati Upādhyāya dance. He even brought forward his two sons and made them fall down at the Lord’s lotus feet.

The two sons of Vallabhācārya were Gopīnātha and Viṭhṭhaleśvara. When Śrī Caitanya Mahāprabhu visited Prayāga in the year 1434 or 1435 Śakābda Era (A.D. 1512 or 1513), Viṭhṭhaleśvara was not yet born. In this regard, one should see Madhya-līlā 18.47.