It's unlikely to be added to the flu shot (H1N1 is type of flu, that emerged off-season, so started off with a shot all of its own, then that was incorporated into the annual shot, just as it would have been if it had emerged on more typical timing)
But it might end up as an annual coronavirus shot against all SARS family expected in circulation.
At the moment there is no plan for children because none of the jabs have been trialled for paediatric use. CEV and CV children age 16 and over can have the jab, and CEV children of any age can be considered for the jab on an individual (off licence) prescription by their hospital consultant.
Pfizer is now testing in the 12+ age group. And it's likely that more paediatric testing will take place idc.
It might become available at some stage, but right now it's not going to be used in DC unless there is an exceptional medical reason. And as posters rightly point out, DC, especially the u11s, are at very little risk of the severe disease and so not in need of a vaccine whose primary action is to prevent severe disease,
If/when we know about the vaccine's role in preventing transmission, there might be further changes to use. Right now we don't know enough.