Hello @Stephanie , Great to see you back here in CC, your contributions have been missed!!
In regards to Clay soils, Lettuces, Swiss Chard (did they originate from Switzerland?), Green beans, broccoli, cabbage and Brussel sprouts (did they originate from Brussels?) radishes, kale, Cauliflower vegetables all are understood to do well.
Have a look at Jacksons Nursery in the UK for Flower ideas to plant, they include Anemones, Astilbe, Asters,Hosta, Red Hot Poker, Geranuims amongst others.
If you have cow dung that also helps attract the Little Blue Ladybird that eats the Aphids. Did you know that the UK used to have Ladybird farms?
Maybe also encourage the Family to dig and have a compost in your garden to help aerate the soil with worms and other precious insects - far better for the environment than those silly little green food leftovers bins that have infiltrated our lands that are scattered across the world - don't start me on the Pink Plastic bags as they just don't do it for many of us!!!