Oh bless you, you sound so overwhelmed! I hope it's okay but I'm going to try and go through your post bit by bit and see if I can help a bit. But remember at 12 months she's a teenager so going through the worst bit. it will get better!
Terrible recall from the garden, last wee at night I’d a nightmare as she just won’t come on. She pulls washing off line and runs off with any child’s toy that’s accidentally left out and just will not listen to us calling her.
If she won't come in, you need to go out with her. Put her on her lead and take her to the toilet like you would a puppy. Ours used to do this and in the end we gave him no choice. You go out on a lead, toilet and back in again to bed. No chance to mess around or bark. He then got a treat once he'd come back in and had his lead taken off. Now he's two we call him in with a bedtime biscuit and he comes right away.
Terrible at jumping up in the kitchen.
Get a baby gate and just stop her going in there. Labs are food orientated and it can be really hard to train it out of them. Easiest thing to do here is set her up for success by not allowing her access in the first place. You can get extra tall ones if you think she might be able to jump a standard one.
Won’t come to us at any point in the house if we call her probably because she associates coming to us with the fun ending and being put away into utility room.
You need to change her association with her name. Pop her on her lead if necessary and practise. Call her name, when she looks at you, treat her. Then slowly move her further away, call her name, she comes, treat. Repeat it multiple times a day. When she does it one room, move rooms, then go upstairs, then eventually out in the garden. Ours will do anything for a cocktail sausage - find what she likes and use it to your advantage!
I thought by now she would be spending the majority of the time with us but she is so difficult no one other than me wants her out in the main areas of the house. So I’m aware she is probably lonely then when she does come out is so over excited.
Pop her on her lead or a house line and keep her with you. You can then control her if she jumps up or displays unwanted behaviour. Reward the good behaviour (sitting, lying calmly) and eventually she'll click that that's what she needs to do.
Today she jumped up to my 5 year old nipped at her fleece pulled her to the ground and dragged her along until I managed to get control off her with a stern voice.
Until you have the jumping and nipping under control please, please don't leave her alone with your DC. Labs are big, strong dogs and she could easily do damage just through sheer overexcitement. Take the dog with you when you leave the room and use a baby gate to keep them safely apart.
I hope none of that sounds too patronising! I went through a really hard time with our beagle when he was a similar age and I was in tears most days! He's now two and a fantastic family pet. I can walk him off-lead and his recall is pretty much flawless - it will get better but you need to be persistent and work at it a lot - good luck 