One of my cats always meows and scratches outside closed doors, I think it's just the pure awkwardness of wanting to get through that particular door just because it is closed!! LOL
She may still be missing her kittens a bit, it takes a while for them to get over something like that. There are a few things that I suggest you try.
1.If you have some small soft toys that you can spare, try putting a couple in her bed, as a sort of substitute kitten.
2. At vets you can buy a plug in thing that puts something into the air that naturally helps a cat to relax. They advertise them a lot around bonfire night.
3. Try not to give her too much attention when she meows. I know it's hard, but you are teaching her that if she wants to get attention all the time then she just has to make a fuss and you will come running.
4. If she has been inside for some time she may be looking for a toilet, so try investing in one of these indoor litter trays with a roof and a door(keeps the smell in).
5. I know this is an obvious one, but, make sure she always has plenty of water to drink available. Cats tend to like cold fresh water, so the more times you can change the water each day, the better.
I hope something here helps:)