Cat in need of a foster family

We have a very friendly, super sweet cat who we are almost certain is pregnant hanging around our house the past couple days. We have three indoor cats of our own and cannot take her in. We have been giving her water and food in the meantime, but with the heat and cars/other animals we know she needs a safe place to be sheltered. We have tried countless rescues in the area that claim they’re all full. We took her to the vet to see if she is microchipped but she’s not. If there is anyone out there who is willing to foster her, please let me know via DM. I am in the Sunrise, Florida area