Heavily pregnant cat needs haven

Lady phoned me today regarding a heavily pregnant cat that's been in her garden the last week. She's feeding it but wants it gone.  Right now I only have a small dog pen to put her into, far too small for a cat and litter of kittens to be stuck in for the next 8 weeks minimum while the kittens are reared and old enough to be homed.  I KNOW there are loads of people out there who have space in their homes or sheds where they could easily offer this poor pet a safe haven while she has her kittens and rears them out of this freezing cold weather.  So PLEASE open your heart and home and don't leave it all to the rescues because we are groaning under the strain.  And kitten season hasn't even started yet.