She succeeded her father but immediately had to deal with her uncle William, who claimed Holland for his own. Ada married Louis II, count of Loon to strengthen her position. She was in such a hurry, that she married even before her father was buried, which caused a scandal.
These events led to the outbreak of the Loon War (1203-1206).
Ada was quickly captured by the supporters of William and taken prisoner in the citadel of Leiden. She was first imprisoned on the island of Texel and afterwards she was taken to John Lackland in the Kingdom of England. William had to accept Louis and Ada as count and countess at a treaty of Bruges in 1206.
Louis managed to get Ada free in 1206, and the couple returned to Loon in 1207. Their reign was short-lived, since Emperor Otto IV regarded William to have more right to the title Count of Holland in 1208.
She did not accept the loss of her county, and Ada and Louis continued the fight. Ada remained childless. Louis died in 1218, leaving Ada to live out the rest of her life in obscurity. She was buried next to her husband in Herkenrode Abbey.
The civil war in Holland became part of a major international war between on one side France and the Hohenstaufen dynasty and on the other side England and the Welfs. William could get Holland through good maneuvering between both sides. Louis and Ada had to give up their claims. Many period histories up to the Protestant Reformation do not include her in the list of rulers of Holland.