When approaching a pedestrian crossing marked in this way, should a driver expect to see a child under the age of 10 riding a bicycle under the supervision of an adult crossing the road at this point?

Why?

Under Polish law, a child under 10 riding a bicycle under adult supervision is treated as a pedestrian. The child may therefore ride across the crossing with the refuge island shown here, and drivers should be prepared for this. An accompanying adult who is cycling must dismount and walk their own bicycle across.

art. 2 pkt 18 Prawa o ruchu drogowym