Bee or spider bite- treating the lawn

Our JRT (Coda) was outside for about 10 minutes. When she came back in, her face was very swollen, she vomitted, and was very lethargic. We took her to the Vet immediately, and they found a bite or sting on the bottom of her paw. They treated her and now she's fine. But we don't know if it was a bee sting or spider bite.

My question has to do with treating our lawn to make it safer for Coda. Getting rid of the clover will help reduce the amount of bees, but what about spiders? Any advice will be appreciated. Thanks in advance.