She's bringing you gifts, and cat food probably tastes better to her than prey. The ferals in our shelter's colony constantly being mice (and sometimes rats) into their feeding room and lay them right inside the door.
Cat: Look mommy, look at what I did!
You: Ewe.
Cat: Did you see mommy? I want you to have it!
You: Ewe.
Cat: I did a good job right? I'm a good hunter and protector eh?
You: Ewe.
Most cats with a steady source of food will kill for fun more than food. They don't need to eat their catches and it's a lot of work to eat a mouse compared to cat food. Crickets and small insects are a chruncy treat so those will usually still be eaten. Some cats do bring in their coaches for their owners as either an urge to help feed their owners or show them how to hunt or to show off, depending on who you ask.
I know in my house, Nightfury brings in mice and lizards for the other two cats. He's been providing for them since they were babies, teaching them to hunt and giving them plenty of practice. Rocket though likes to leave hers outside, my guess is her feral starting made her less inclined to share. But my guys rarely eat the mice they catch and some mice even survive the experience (assuming they aren't caught by Rocket).
Wow...I love these stories. My other 2 cats LOVE their buggies. While looking at a kill, a pit bull ambled up our driveway. Our male ran towards him arched, tail fluffed and ready to attack. I guess my family is helpless. I've got a feeder and a protector.