What does Daniel 11:7 mean?

In or around the year 536 BC (Daniel 10:1), the prophet Daniel received another prophetic vision. This is being explained to him by an angel (Daniel 10:18–21; 11:2), likely Gabriel (Daniel 8:15–16; 9:21–22; 10:10–11; Luke 1:26). So far, the angel has made predictions historically fulfilled more than two hundred years later through the lives of men such as Xerxes and Alexander the Great (Daniel 11:3–4). Also prophesied was the disastrous political plotting which saw Berenice, the daughter of Egypt's Ptolemy II Philadelphus, murdered not very long after her wedding to Syria's Antiochus II Theos (Daniel 11:5–6).

Here, the angel points to someone who shares ancestry with "her," meaning the "daughter" of prior verses. This person is a "branch" of "her roots." That would not imply a husband or child, but someone with common origins: a sibling. This figure will strike against the king of the north, taking revenge along with enormous spoils (Daniel 11:8). This will lead to further conflicts (Daniel 11:9–13).

As with all prophecies, history eventually proves that God's Word is truth (Daniel 11:2). Antiochus II died only a few months later, likely poisoned by his once-and-again wife: Berenice's rival, Laodice. The vengeful queen also seems to have had Berenice assassinated in the resulting chaos. Her first son, Seleucus II Callinicus, assumed a shaky hold on the throne of the empire. At the time of her death, Berenice's brother, Ptolemy III Euergetes, had assumed rule over Egypt. Seeking revenge, Euergetes immediately invaded from the south. He successfully defeated Seleucus II and returned to Egypt having captured tremendous wealth. He also eventually captured and executed Laodice, who was then supporting her second son, Antiochus Hierax, in his struggle for power with Seleucus II.