Our cat keeps on transferring her litter from one place to another.

Sounds like your idea of a good, comfy place is different than momma kitty's. Maybe try putting a box with an old blanket or something in it where she has the babies now. If she leaves them there, you might be able to just move the whole box after awhile. I noticed our cats liked to feel enclosed and secure when they had the babies. Try to create the same kind of place as she is looking for and moving to.

Mommy Cat thinks she is protecting her kittens. They like dark and warm places for their babies. If the place you made her is in the open she will try to relocate to a darker place like a closet or under the beds.

Cat are very independent and like to make their own choices. we had a mother cat that decided to keep her kittens behind the sofa we would put them in a nice box in a closet but she then would move them back to behind the sofa. it really wasn't a very quiet place ether. finally we just let her keep them back there. They did fine.

Cats can be picky sometimes. Over the years, I've noticed that both inside & outside cats move their kittens around. Outside (feral) cats move kittens mostly because of preditors and safety issues -- moving protects their kittens from being killed. This might be one reason your Momma cat is moving her kittens. She wants them to be safe. If Momma cat is a first-time Mom, she might be unsure where in your house is the best place to raise them, loud noises also make a difference 'cause most cats don't like loud noises (maybe one place is quieter than another)...or it might just be she doesn't like the smell or texture of the fabrics -- her hormones have changed due to her pregnancy & now producing milk for her kittens. This will sometimes change what she likes/dislikes about her surroundings. Basically, she's trying to make sure her kittens have 1.) the safest place and 2.) a place to grow and develop the best. I have not found a way to encourage my Momma cats to stay where I prefer -- usually, they have a mind of their own. I find if I don't force the issue, they sometimes find "my choice" best. If I force the issue, it seems they deliberately DON'T choose my preference just to make their point. Hope you, Momma cat & kittens have long & happy lives together!