Not only will there be no male or female in heaven, but no fleshly bodies. 1 John 3:2, “Beloved, we are God’s children now; it does not yet appear what we shall be, but we know that when he appears we shall be like him, for we shall see him as he is.” The natural man cannot grasp what spirit, heavenly bodies will be like, but the characters we have developed and the personalities for which the Lord chose us in the first place, will remain the same. And that is truly how we know one another. Just think for a moment. If a person is in costume, very often they are still recognizable because of gestures, word choices, etc. Mary recognized Jesus (when He appeared as a gardener) by a word (John 20:15, 16). The disciples on the road to Emmaus realized they had been talking with Jesus by the way He broke bread (Luke 24:30, 31).
Respecting the earthly resurrection, men will return very similarly to how they died; therefore, knowing them will not be an issue. As they grow toward perfection, nothing will alter their basic uniqueness. Knowing our loved ones will be no problem!