sounds like she not too sure what is happening and when - and who is where.
can you make a big wall calendar for the week with a white board and stickers, - if you ahave ve magnetic white board you can buy stick on amgnets from art shop and put on back of photos - as well as being able tow rite with board marker. so she can see for the week what is happening and where she wil be and when - you could put days of weeks and have stickers - or use stick on magnets - use photos and pictures to who she will be with and what will be happening and when. does dad have his own house? what would make her confused about where he is sleeping? is she worried he has nowhere to sleep?
go from left to right with days of week - you could have it so the one on left is always today or if too much hassle start with monday - every day you go and say with her today is tuesday (or whatever) so you will sleep here with mummy - but tomorrow is wednesday you will sleep at granma's house --etc.
so days left to right, tehn under each day the schedule as visual timetable going from top morning to bottom night time .
so you would have pics of her, her sibling, granma, daddy, mummy, nursery, home , a bed etc - so she can visualise and see where her bed or herself will be each day and night.
so you would need multiple pictures of each main activity.
get your six year old to help you do the week schedule eg on sunday evening.
once they know exactly where they wil be and when and can visulaise it it will help cut down on anxiety and knowing what is happening when and with who. .
it will also help with learning to read and learning days of week too!! ie have picture of bed with word bed or sleep under it, wirite "mummy" under yur photo etc.
you could have a big star or whatever to show which day is "today" ie you do the schedule on sunday evening then each day you would move the star to "today" then go thru wiht her today is xxday, you will go to xx and xx and sleep at xxxx. then tomorrow is xx day and look you will go to xx and xx and sleeep at xxxx.
otherwise - also - try and cut on cleaning /cooking eg hire a cleaner - freeze meals, quick cook eg pasta...
mine are older and they do differentiate between the days when is routine afterschool club pick up evening, cooking etc - versus a "proper" day eg weekend when we can do other stuff. so yes i do know what you mean.... just try and plan days where you can leave cooking (just eat out of the fridge picnic food or they make cook and clean with you) and focus on nice stuff togetehr.