It is possible to charge one phone battery from another by directly linking their positive and negative contacts with two wires. I know this is probably considered esoteric knowledge by women's standards, but still.
Also, having a dedicated rescue app already puts the story above the slop, but it's still nowhere near enough. Realistically, a city where monsters flood through random gates will never look normal. It will be completely evacuated, because fighting monsters in urban environments is a nightmare. If the city isn't evacuated, it will at least be prepared for sieges, with food and water supplies, weapon supplies, building roofs connected by bridges, etc. And not only the army, but every citizen will be obliged to take part in training and form some standby units.