My DD is also 8, will be 9 in March - and although she lives with her dad I've found she's doing similar things when she's here with us.

We don't really ask a lot of her, other than tidying her room, keeping her bathroom tidy and putting her clothes in the wash. I'm thinking about starting to get her to help with the dishes, but she's only with us 2 days a fortnight so don't really want that time to be all about chores. This will change when she comes to live with us fulltime in a couple of years (we're looking at year 7).

Most of the time it was a constant "are you done yet" to get her to do her room, then we'd go check and she'd only half done it, or having to remind her to empty the bathtub when she's finished with it and to take her clothes out of the bathroom. She is getting better now though. I'd say give it time, keep the consistency and things will gradually start to improve.