The PHD Minim range don't have a 'neck collar' - not good in low temps. The ME Classic I still have for sale is heavier but a much better design for below freezing temps. I echo Kate and suggest a lightweight breathable sleeping bag cover would be a good idea if you are worried about keeping dry.
Women in general sleep about 10 degrees colder than men - so unless you know different, you need to aim for a bag rated warmer than -10c comfort, to keep warm at that temp. A secondhand down bag is likely the only way you will meet your criteria.