Still plenty of time to sow a lot of vegetables; peas, runner beans, carrots, beetroot, endive, radish, cabbage, celery, lettuce and swiss chard all spring to mind and I'm sure there are more!

.............as well as Sweetcorn, spring onions, courgettes, marrow, squashes. Don't forget cut flower too. You can buy stocks, sweet peas and lot of other stuff for cut flower

If she is a beginner Sweet Corn is complicated.

I would just say Runner Beans, with a root of Lemon
Balm alongside to ward off the Black Fly. If they dont
infest the birds will leave her Bean Flowers alone and she will get Runner Beans 3 weeks earlier.

Success is encourages young people.

Malva Moschata Alba flowers encourage the Hoverflies
to visit late evenings, to feed on the White Fly larvae on her
winter cabbages until Sept 8th when they will need spraying. Malva Moschata Alba will self seed giving her
plants to use next year for this purpose, so digging in the winter is better than rotovation which chops up these most valuable plants. Lists of plants to try is costly for seed.
Learning is more valuable. She will remember.

If she likes flowers for cutting, the pot 'mums you get in summer and autumn can be planted out, and although they've been treated with a dwarfing agent for this year, they will grow to a normal size next year, so if you see any marked down in the supermarket or GC, could be a bargain.
I think the oriental salads like mibuna, mizuna and pak choi need sowing after mid-summer to prevent bolting.

DianneBulley.....why is sweetcorn complicated ? Plant in a block rather than a line and you'll do fine. Really can't understand your comments

What about Swiss chard? Good stir fry material all winter and decorative as well. And how about kale, again you can pull it all winter as you take leaves off it rather than uprooting the plant, so you need fewer plants than cabbages..

Oops forgot spinach beet! And agree sweetcorn is not complicated our, very inexperienced, neighbour grows from seed and does reasonably well every year.

Sorry Badfish. Some Sweetcorn do not carry pods.
I have seen fields of them with very few pods on.
The recommended variety is Lark F1 hybrid T&M if they
have any left.