Just keep a good eye on her if she is getting some loose poos - you never know!
I know you have plenty of snow there but are you still able to take her out for walks - soft snow and no icy patches would be great, and I know some folks wont agree, but it is so important for her to keep moving around, especially this close to foaling, and as long as she can walk on a fair depth of soft snow with a grass surface underneath, then there is little chance of her slipping up.
Any more change in her udder yet?