How many {mother} are to/by {Eleanor of Aquitaine} ?
Who is Eleanor of Aquitaine's mother?
Who was the mother of Eleanor of Aquitaine?
SELECT ( COUNT ( ?w ) AS ?d ) { ?w property:mother resource:Eleanor_of_Aquitaine }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P25> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q178525 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P25 wd:Q178525 }
10