This is just going over old ground.
Sonnie does not appear to be the bears name, but a pet name for son. So it is from daughter and son, Dora and Glyn.
Earlier a possible family was found with children of the right names, right ages, right area, and with father serving abroad.
Until that family is ruled in or out, then there is little point in further specualtion. If that lead goes nowhere then we will have to think again.
The mods have assured us this lead will be followed up, and ask for patience as it will take time.
So lets just wait till they give us an update.