Sree Sree Guru Gauranga Jayatah!
In Goloka-Vrindavan, Krishna, Radha and almost all gopis are kishore — adolescent. Those who are elders, parents etc., have grown up bodies, bigger in size, but those are also eternal. Krishna and all cowherd boys are almost of the same size, only Balaram is taller.
As there is no birth and death and as all relationships are eternal, those relationships are very delightful and everlasting. Also, there is no influence of a time factor like we find in this material world, there is no actual existence of past and future, everything is in the present in the transcendental realm of Vraja dham. The sweet pastimes are arranged by Yogamaya to relish the sweet pure love, where the Supreme Lord Sri Krishna and His Absolute Counterpart Spiritual Potency Srimati Radha forget themselves.
--- Jagad-guru His Divine Grace Srila Bhakti Ballabh Tirtha Goswami Maharaj