Complex sentence: She was eventually sent back to Spain at the request of her parents, and Isabella returned to them devoutly religious and undergoing efforts to starve and scourge herself, something she would do for much of the rest of her life as part of her mourning for Afonso.
Split into simpler sentences: She was eventually sent back to Spain at the request of her parents, and Isabella returned to them devoutly religious. She underwent efforts to starve and scourge herself, something she would do for much of the rest of her life as part of her mourning for Afonso.