|Marie Henri d'Arbois de Jubainville via Wikimedia Commons|
The couple had two children together, a son probably named Theobald and a daughter named Jeanne. Their son died tragically when his nurse dropped him from the battlements of the family's castle at Estella. Baby Jeanne was about a year old when King Henry, which left her as Queen and Blanche as her regent. That did not stop her from remarrying two years later into one of the most powerful houses of the day, when she married Edmund Earl of Lancaster, the second son of King Henry III of England and his Queen Eleanor of Provence (read about her in Cinderella Sisters Part 2).
From there, she negotiated the marriage of her daughter to her cousin Philip IV of France, starting an on-and-off personal union between France and Navarre that would continue until Navarre finally became part of France a few centuries later.
With Edmund, she had four children and started the House of Lancaster that would eventually fight their cousins the Yorks in the Wars of the Roses. Within a few generations, her descendants would sit on the thrones of France, England, Portugal, Aragon, and Scotland.
For more about Blanche:
Blanche of Artois, Queen of Navarre on Edward II