My cat who always poops in the garden let out a very loud deep meow and pooped in the house

Hi. It’s midnight here and I heard my cat outside my room let out the loudest couple of meows. I noticed a smell but couldn’t see anything. she was laying down and a little bit of panting and slight drooling. I then noticed poop. She was walking funny. Now she seems more settled and those symptoms seemed to have stopped. She’s sitting / laying how she normally does but not sleeping, just looking around. So I dunno what to do whether to wait til the morning or what now she seems somewhat settled. I got scared she had an injury but her walking seems better now. Does anyone know what this could be? If she ate something dodgy? I really don’t know what cos she doesn’t go out much only in our back garden. It’s hot today but it’s been hotter. I’m very confused and distressed and can’t understand what has caused this as I’ve never seen it.