Problem: Continue the following story.

After stopping when running, Betty needed help from Rachel treat their asthma because 
Here's how I want to continue it: Rachel has it too.

Problem: Continue the following story.

Maria dressed Elena's large chest wound with gauze and antibacterial ointment because 
Here's how I want to continue it: Maria was concerned about the wound.

Problem: Continue the following story.

At the coffee shop Erin prepared the beverage for Christine, since 
Here's how I want to continue it:
Christine was the customer.