Guessing an approximate due date!

So 10 days ago, I took on a pregnant foster cat. She is absolutely lovely. Since 10 days ago she has doubled in size. She is now huge! The only trouble is not knowing her due date! It's torture! In 11 days time I'm going away for the weekend. I need her to have them either before I go or hold on till I get back. But I really hope it's soon!! I have added some photos so you can all have a good guess... and maybe a guess on how many kittens too!

She has started to lay like this with her back legs for the past 3 days. Was hoping it was a sign she might drop soon!

She is sleeping a lot and I know that is a sign she could be due soon! But she still is eating like a horse. But that might be because in her last home she wasn't sure when her next meal would be... she is rather skinny (minus the baby bump)