Q.marguerite plants
This plant suddenly appeared in my garden last year. It had beautiful leaves and white daisy flowers. I didn’t know what to do over winter, so I did nothing. This year, it quadrupled in size and I was thrilled and anxiously waiting for the flowers. However, no flowers appeared. The foliage is gorgeous — but no flowers. What did I do wrong?? How can I get it to flower again?

Depending on your growing zone, you may have Marguerite Daisy, or Shasta Daisy plants.
Lack of flowers could be an excess of nitrogen in the soil. Don't over fertilize your plants.
You can do a soil test to verify the soil nutrients.
Adding some organic Bone Meal for a phosphorous boost can help with flower production.
Here are some links with more information.
https://www.gardeningknowhow.com/ornamental/flowers/marguerite-daisies/marguerite-daisy-flowers.htm
https://www.gardeningknowhow.com/ornamental/flowers/shasta-daisy/planting-shasta-daisies.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/bone-meal-fertilizer.htm