During one of these flashes, she has a quick verbal exchange with a woman in the store. The woman addresses her, MC makes a comment, and the woman responds. Then on to the action.
It has occurred to me that the MC's comment is important. Yes, it's just one line of dialog that serves the purpose of establishing her guard is up, that she senses imminent danger, but it's more than that. It's the first time the reader will hear her speak.
What she says, and how she says it, will leave an impression on the reader. Her comment must reflect the person she is, and it must have a clever, larger-than-life quality that attracts her to the reading audience. It's gotta have zing.
Auditioning possible lines has been a great exercise in character development. When I found the right one, it clicked. It felt right. First time readers won't know her intimately after reading her first line, but I hope her comment works on them like a tantalizing smell coming from the oven, promising something delicious is about to be served.
How important to you, or to your story, is your main character's first line of dialog?