First you do not have to do ANY of the things you are doing. Who in the hell do they think they are? For starters if you make any noise during social hours (I think it's something like 8am-11pm but I could be wrong) then she can whinge all she likes, there is nothing that can be done about it.
Make all the noise you like.
Yes she has the right to sleep in if she likes, but you have the right to get on with your life and if she doesn't like it she can move elsewhere - you were there first. You should not cater to her every whim. Tell her to get ear plugs.
Live your life normally, let your kids play how they like - the reason she is like that is because you give in to her. As long as your kids are not screaming all day every day then she cannot do anything about it as there is a certain level of 'reasonable noise' allowed by law.
Also document every instance should she make a complaint. Try and record her. If she tries to lodge a complaint with the council, she won't get far. Trust me had neighbours who were loud ALL the time - a young signle couple they bounced tennis balls off our bedroom wall til 3am, threw cigarette buts in our garden almost set our fence on fire with a BBQ, had raging loud parties when the football was on, screamed and ahouted at all hours - countacted the council there was nothing they could do even though we had evidence. You are fine and being more than reasonable - I would have loved to have you as a neighbour rather than those a-holes.
Sounds about right - no kids and no pets they have no idea what its like. Suggest they save up and buy a detached house in the middle of nowhere
You are not ruining her life - SHE is ruining YOURS and I would suggest you tell her so and the next time she complains tell her to fck off, wind her neck back over her side of the fence and fcking get over herself. Does she think she's the Queen or something?
You have the right to enjoy your home and for your kids to as well if she doesn't like it and if she shouts over the fence at your kids - call the police.
What a self entitled little bitch.