Oh the sanctimonious super mummies have come out to play!
Anyway, OP, if you can't have a moan here, then where?!
8 weeks one on one with an only child can be a bit much.
I find that making plans, chucking in a few tennis or swimming sessions (or whatever is on offer locally) and being super sociable at the school gate and swapping numbers with other local parents of kids in DC class works well.
Also, structure the day a bit. I find going out in the morning 9even if just library or local pool) then pm can be at home (play and telly).
where do you live? Most places have lots on offer if you know where to look (national trust, petting farms, outdoor lido's, cheap cinema in the mornings). and projects at home (clearing out the garage together, washing the car together), so you get things done. I make my kids help with the gardening (weeding etc.)
You really do not have to entertain her too much, just make her join in with what you'd normally do. Go to the supermarket and have a coffee (hot choc) together can break up the day. You read a paper, she gets a magazine.
6 is quite a fun age, but still quite full on. my 6 yr old would drive me mad if he didn't have an older brother to play with!