Oh op you are really working hard and it is really tough, please keep positive.
Personally l would think what makes my life easier,
ie, stop the messy play in the house, its not compulsory
Don't have washing out till after bedtime.
Only clean once they are in bed.
Organise fast easy meals and freeze, so at the end of the day when you are tired dinner is fast and easy.
I found getting up and going to the park for breakfast(we used to buy croissants on the way, we had to go early as we had a lively dog who needed walking) was really helpful, just out of bed dressed and straight out with a ball or frizbee. Take coffee for you and easy breakfast for them.
No mess to come back to and some energy dissipated, plus the weathers lovely ....
Can you pack sandwiches for lots of picnics for some lunches, if DD wants to throw them let her! Open space and ball games works wonders! You just let her be and relax a bit.
Re other activities, l had to assume my son had to miss out if his sister was misbehaving and we had to leave, it was only for a couple of months and in my eyes unavoidable.
You HAVE to stick to consequences and they have to be immediate....ie in this playspace l expect X,Y,Z behavior or we leave straight away, be fully prepared to leave whatever, no second chances....she will not keep ruining her fun events l can tell you.
One concession from DH ruins it all, so take over fully to address this behavior, really throw the boundaries down, stay calm and follow through, remember she will then ALWAYS know you mean what you say, which is very useful later!
Hang in there op, from someone who has been there..