Very typical of the mid 50s. She's wearing a smart suit that suggests middle class, middle aged. 

Should be a bystander, but she's following the boy almost in step, oddly. On the other hand, why would he need his aunt to take him to school?

AND if everyone else is wearing summer dresses and light headscarves, why is she in a suit, AND if it's summer, aren't the schools on holiday?  

Posted by: @coracle

On the other hand, why would he need his aunt to take him to school?

Swim lessons? Just kidding (sort of).

Well, if they set it up to where his mom is sick and his dad is out of the picture and he just moved in with his Aunt and Uncle, he potentially wouldn't know where anything is at, so she could be escorting him to any number of places, and he doesn't want anything to do with her. Maybe????

But I'm more curious if anyone recognizes the actress there. Again, she could just be an extra and not have a major role in the film. Just something that caught my eye.

@fantasia but not in his thick school uniform, with his satchel -  a smart new one with the extra pocket. She has clearly bought him a new uniform with room to grow (the blazer looks long on the right side of the photo)

(NB boys at my school in the early 60s didn't wear their satchel across the body as on this photo, but on their back, with the long strap around the front of their shoulders and back of the neck)