It's one of the more spectacular forms of Tropical Hibiscus, probably 'Fiesta'. That variety name is uncertain, though--there are so many!

Not sure what happened to my reply, Tug, which I tried to send to you an hour ago. But your answer was exactly what I hoped for and I sent it almost word for word back to her, making out it was my own reply. she has just written back saying it's definitlely a Hibiscus and she bought it 15 years ago, but knows nothing else about it.
I told her I'd do a little more research !

I've been looking at photos, and I'm now pretty sure that it is 'Fiesta'. 15 years ago sounds just about right--it was much more common in the market, then, than it is now.

Thanks again T, while I hardly know the difference between a dandelion and a daffodil I have really impressed my daughter with my ( your)? reply.

Dads should always be heroes. Sometimes even "super"! :)