I can't say I have any experience with this (ie no children of my own)....It sounds incredibly frustrating. My sister and I were about 3 years apart and did our fair share of fighting when we were younger. We shared a room too...

Are there any activities that your daughters can do by themselves (ie not together)? Is it any better that way, or so they just try to distract each other?

Would you older daughter enjoy teaching your younger daughter something new? I remember my sister learnt the recorder at school and I loved it when she come home and gave me a lesson!

Do you have a library nearby? Perhaps Moni (I've just noticed the names in your signiture!) could choose some books for Miah to read to her.

Good luck!