Thanks for your responses, she's pooing & weeing (I couldn't think of a way to put it without sounding crude ) Yeah it gets cleaned up straight away, she has been really skinny since she had the kits but seems to be eating and drinking fine and she always was quite skinny.

She acts really weird actually, she'll leave the kittens & wander around aimlessly. She'll come for a stroke when i call her then get irritated and walk off when I try stroking her. If I stroke her while she's with the kittens she seems happy. She walks to the back of the garden then walks back inside. She keeps moving the kittens into ridiculous places.... my sister woke up one morning to find that they were gone & was looking around for ages, the cat was meowing at her. Eventually she found them in the back of the airing cupboard tucked behind a massive pile of towels... the cat couldn't even get there to feed them