When we get to Heaven we’re going to know more than we know now. I certainly don’t think we’ll know less. While we shouldn’t be dogmatic, I think it is fair to suggest that yes, we’ll know each other and rejoice with each other (1 Cor. 13:12).
As far as what people in Heaven know about our lives on earth, Scripture does not answer this question clearly. However, we have a little material on which to base the belief that she may know something. (Note that I say may know, not does know.) First, Moses and Elijah went from Heaven to the Mount of Transfiguration in order to speak with the Lord about His impending death. They had deeper insights into His mission than did the disciples. Were they the only ones in Heaven with the knowledge? Possibly not.
Second, Revelation 6:9–11 notes the concern of some who were murdered for their faith. They wanted to know when God would avenge their blood. They were not given a complete answer; they were told only to wait, “until the full number of their fellow servants, brothers and sisters, were killed just as they has been.” Thus, they were assured that justice would be done—according to God’s timetable.
Heaven might not be heavenly if the ransomed of the Lord knew everything that happens on earth. On the other hand, everybody in Heaven sees things from God’s perspective. If He who is Love can cope with the knowledge of tragic events in the families of His people on earth, so can the family members already in Heaven. When all is said, we do not know how much they know about happenings on earth.