She brushed past without seeing me.

I followed them at a distance.

All three were laughing.

At what?
I can guess; she because she was eighteen, they for joy to be with her.

At the end of the marketplace they turned to the left, followed the railings of the church, and bent their steps toward the Rue St.Sulpice, doubtless to take home M.Flamaran, whose cineraria blazed amid the crowd.