The police and pro-government mobs responded with deadly force, even against unarmed protesters, according to human-rights observers, shooting and killing people across the nation.

Ms. Valdivia said she wondered why nobody helped them. First one fell in her neighborhood, then a second. After the third was shot, she hopped on her new moped and came to their assistance herself.

Ms. Valdivia spent two months running what she considered a humanitarian command post, administering first aid and providing lunch to protesters who were snarling traffic with improvised road blocks. She learned how to use homemade mortars, she said, although she mostly left the weaponry to the men.

Then a relative phoned with a warning: “Don’t even think of coming here. There are about 25 police officers in your house, and they are destroying it.”

She fled and never looked back, leaving behind three shuttered businesses, a house, a car, the scooter — and, for his own safety, her 7-year-old son, put in the care of his father, who has sided with the government and sometimes sends Ms. Valdivia angry text messages about her allegiances.

“For now, I have to be with my people,” she said, referring to her fellow fugitives. “In the future, when Nicaragua is free, my son is going to enjoy all of that.”