It is much more normal than people realise for bed wetting to take place amongst youngsters much older than 7 years of age. Most of these DO eventually sort it out as they grow older.
What NOT to do, is to make any sort of fuss about it. Horrible idea star charts or any other sort of 'reward' system - as this is more or less saying that the child is in control and wets deliberately,
Laid back approach, - if the wetting wakes them, get them to change their night clothes etc. Keep a waterproof mattress cover in place/
Many years ago, one of my neighbours was told by GP to use one of those alarm systems for her 11-year old bed wetting son. Put it in place, buzzer went off in night, whole family woken up, EXCEPT for the lad himself.
Deep sleepers are often bed wetters. One of my children was a very deep sleeper, even when I tried to get him up when I was going to bed, in order to use the loo, he had no idea where he was or what he was doing. One time, just stopped him standing at the top of stairs getting ready to pee!!!
When one of my foster children (a bed wetter) went into one of my older daughter's bedrooms at 2 am to say his bed was wet, she told him to change his pj's and get into bed with her - which he did. Following morning I woke to find house in chaos, as the big water tank in the loft had overflowed all night, bringing down ceiling at that childs room and flooded right through to ground floor!!!!