I would say yes, test her throughout the night. Maybe a little more frequently, say hourly for the next two hours to see how much it is affecting her, and then you can stretch it to every few hours. As far as food is concerned, if she's actually hypo when you test, the most important thing is just getting the carbs in her, so whatever she will eat most happily! If that's a teaspoon of honey followed by a biscuit or two then that's fine, just something sugary and then something starchy. If her blood sugar is dropping but not yet under 4, you don't need to worry too much about the fast acting carbs. Just keep a close eye and adjust as needed, and it's probably better to be running a bit high just for tonight! For levemir in the morning, I would reduce it depending on how low she has been dropping overnight/how often you've had to wake her to eat. It may be that you don't need to half it, perhaps reduce it to 7 or 8 units. Again, keep an eye on her sugars in the morning but it should start to settle down as tonight's levemir runs out.
xx