Divorce in the District, in Montgomery County and in Fairfax are three different searches
Your keyword list is not one list, it is a grid of jurisdiction by matter type.
Start by writing the grid down. Down one side, the places a case can land: the District, Montgomery County, Prince George's, Arlington, Alexandria, Fairfax County, Falls Church. Across the top, the matter types you actually take: divorce, custody, support, modification, protective orders, agreements. Most firms have four or five real service lines and six or seven real filing locations, and almost none of them have pages for the combinations.
The searcher rarely types the courthouse. They type where they live and what is happening to them. Someone in Silver Spring types Silver Spring. Someone in Old Town types Alexandria. The page that ranks and converts for them is the one that mentions their side of the metro and the court their case would go to, in ordinary prose, near the top.
We will not guess your volumes. Anyone who quotes you monthly search numbers for a phrase like divorce lawyer Arlington before pulling the data is making them up. The honest sequence is to pull the query report you already have in Search Console, sort by jurisdiction, and see which of those grid cells already gets impressions with no page behind them.
The grid also tells you what not to build. If your firm files in the District and Maryland only, the Virginia cells are content that generates inquiries you have to turn away.