I believe the best way to litter train your fur-baby would be to put her in a smaller, tiled room like the bathroom for a while. Keep her food, water, litter box, and bed/blankie in there, and go inside to play with her, interact with her, give her affection, etc. Keep her in there for days if you need to, the more times she uses the box, the more likely she'll use it in the future. If she's used it, say 10/10 times, better chance she'll keep using the box. You'll also need to get extra boxes throughout your house when you do let her out. Kittens her age are equivalent to toddlers who can't "guestimate" when they need to go, and how far their litter boxes truly are.

In the meantime, you'll need to invest in a LOT of enzyme cleaners to soak all of your bedding/mattress to rid of the smell. Though you can't smell it, your kitty will. A cat's olfactory is known to be about 14 times stronger than a human's. Febreze probably won't work, unfortunately. A good soaking, like overnight, will help break up urine particles so you can wash them out. It's great you got a mattress protector, though, very smart!

The biting and suckling is because she was seperated from mom and littermates early. I think there's other current threads on that, too. You've opted for a young kitty, so I hope you're ready for a heck of a ride! Hang in there!

 

I believe the best way to litter train your fur-baby would be to put her in a smaller, tiled room like the bathroom for a while. Keep her food, water, litter box, and bed/blankie in there,

Is it okay to place said litter box in the bathtub (assuming the cat/kitten is easily able to jump in and out?)

 

She won't go near the bath. She has 2 litter boxes one in the livingroom and one in my bedroom because those are the places she is near most. I did keep her in the bedroom for a week with one litter box but she got fed up and kept meowing at the door to come out. So I got another litter box. I soaked the mattress with a biological laundry detergent so it should of got all the enzymes out, the febreeze was just to add to it. She hasn't peed since last week (outside the litter box)... BUT her litter box is due to be cleaned out fully. Should I leave a small bit of dirty litter in there and see if that helps?

Yes I am very cross with the 'breeder' who sold me her. I thought she was 8 weeks turns out she was 6 1/2 I did tell her friend who had advertised them for her that I wasn't very pleased about it. She is generally a very loving kitten. She is very affectionate. But she bites and she plays too rough which i am trying to teach her is not ok. I won't play with her if she bites me, I stop and remove myself.

 

She hasn't peed since last week (outside the litter box)... BUT her litter box is due to be cleaned out fully. Should I leave a small bit of dirty litter in there and see if that helps?

Well if she's been consistent about using the litter box, that's great progress! I have never used old litter in mixed with the new, but did try the "litter attractant" by Dr. Elsey with great success, given you use it on unscented scoopable clay litter. I've tried wood pellets and one of my kittens didn't favor that very much, so I was constantly cleaning up after him. NOT fun!

Hopefully your Miu has adjusted well and will continue to do so! Crossing fingers for you!

 

I tipped the litter out but didn't wipe the bottom this week as every time I spray the bottom with cleaner is when she pees outside the tray so I am hoping this is it. But I will have to clean the tray next week because of hygiene.

She is very good she only had 2 poo accidents and those where when I first got her on the first day. The pee accidents are what persist she's had 3 pee accidents and it's always after I completely change the litter, but I'm not happy having dirty litter boxes and I doubt she would be long term either.

She is currently asleep on the sofa.

She does have a few attachment issues too. When I go out to work she does meow when I get back and cling to me. I had considered getting another kitten for her for company but I only really wanted one cat and I can't get her spayed yet because she is too small.

 

Sounds like she may not like what you are using to clean the box with. Maybe try a different one? Is the cleaner scented? It could also be that you are cleaning it too well and she's having problems with that.
You'll want to wait until she is about 4 or 5 months old or 4 lbs before you spay her. Doing it any younger or smaller can sometimes cause complications. Either during the surgery or later in life.
The suckling thing is most likely going to be something she does her entire life. My cat, Pip, is 3 now and he lost his mother when he was 4 weeks old. He's never stopped trying to nurse on blankets.
For the attachment issues, don't make a fuss over her when you come home from work and don't make a big deal out of leaving. If she's being clingy when you get home ignore her until she calms down. Make sure she has a lot to do while you are gone. Food toys are amazing for this. I wouldn't worry about getting a second cat for her. She will adjust to being alone after a few weeks. But encouraging her (even by accident) attachment issues can cause severe separation anxiety when she is older. You may also want to get a comfort zone diffuser or collar. They release the same pheromones that a lactating queen does when she is nursing her kittens. That will help her be more comfortable when you are gone.
As far as aggressive hand play goes. Don't let her play with your hands at all. Hands are never a toy. My cats have all LOVED peacock feathers. You can get them fairly cheep at most craft stores. Like Hobby Lobby or Michael's. Usually for about a dollar. Just wiggle it around her. The cat wands are also great but can be expensive.