The snapshot was taken just months after I lost my mum, and not everyone in it is still with us. But it is an image of survival, capturing the aftermath of grief and the beforemath of future losses

I remember the moment this photo was taken: five years ago, on my partner Claire’s birthday, in a National Trust for Scotland garden six miles east of Edinburgh. We were standing on a wooden deck, an ideal spot for pond-dipping with the kids and a lesser-known viewing platform for trainspotters. This is where my autistic son, then six, loved (and still loves) to jump in tandem with the ScotRail trains toggling back and forth in the middle distance. We had just eaten a small, hasty birthday picnic of pastries and Nosecco. We wandered down through the walled garden to the wild meadow encircling a pond. We ended up where we always end up. On our deck.

Somehow I knew it was a moment worth freezing in time. I gave our dear friend Dawn – whose husband had recently died and who was slowly, informally becoming part of our family – my phone. She took two photos. In the first, two of the five subjects – dog and son – are showing their rear ends to the lens. In the second – this one – almost all of us are looking directly at the lens. Some of us even look happy. Result!