Where it is. Gāndhāra was an ancient region of the northwest of the Subcontinent — the Peshawar valley and the Swat valley, extending to Taxila (Takṣhaśhilā) and towards Kabul, in present-day north-western Pakistan and eastern Afghanistan. The chapter locates the art style in “the western regions of Punjab”. It sat on the routes by which the Indo-Greeks, Śhakas and Kuṣhāṇas entered India — which is exactly why its art blends Greco-Roman and Indian features.
The Mahābhārata connection. Yes — Gāndhārī, whose very name means ‘the woman of Gāndhāra'. She was the princess of Gāndhāra who married the blind king Dhṛitarāṣhṭra and bound her own eyes with a cloth so as to share her husband's condition. She was the mother of the hundred Kauravas, including Duryodhana. Her brother was Śhakuni, the prince of Gāndhāra whose dice-game brought about the exile of the Pāṇḍavas.
Her brother: Śhakuni, prince of Gāndhāra