Stray? kitty

I hear her now throughout the day, outside windows and doors, mewing. She’s been hanging around for a few days, peering into the windows and doors when we leave the blinds cracked or the inside door ajar. Sally has barely noticed but Jack has spent a fair amount of time opposite the glass, rolling around and rubbing his head toward her, only to be met with mirrored rolling, rubbing action. Somebody’s in neutered loooooove. I can’t let them hang out because he’s not up on his shots. And the kitty can’t exactly come in because we’re paranoid about fleas and such, not to mention my pregnant-ness. We’ve put a couple of dishes of food out for her and she’s eaten them ravenously. I can’t tell if she’s young or just small. Both, maybe. I peg her at about a year old. She’s thin but not skinny. Very sweet, always trying to dart in the door. I could have sworn not long ago I heard her kill a bird and bring it to the door. I opened up, expecting to see a robin carcass but it turns out I was just imagining things.