Suddenly unsettled

So i have a 9 nearly 10 month old black labrador. She entered her first heat cycle on the 15th of Jan and has been fine until last night where suddenly she just won't settle in her crate. Is this just the teenage era people talk about? Do we just have to stay strong? She has toileted just before going down and is behaving normally until its time for bed. She goes in no issue going into her crate but the minute we go to bed shes scratching and barking. I thought this was behind us but maybe not. Any advice on how to get through this would be appreciated.