Question: Margaret of Huntingdon (died before 1228) was the eldest daughter of David, Earl of Huntingdon (died 1219) and his wife, Maud (died 1233), sister of which earl that died in 1232, was one of the "old school" of Anglo-Norman barons whose loyalty to the Angevin dynasty was consistent but contingent on the receipt of lucrative favours? 
Sentence (from "Margaret of Huntingdon, Lady of Galloway"): Margaret and Alan's son, Thomas—Alan's only legitimate son—may have lived into the 1220s, but died young.
Relevant evidence: No