I'm not complaining but...

[ElfOnTheTopShelf]

... is it far too much for my DD to be sleeping for three/four hours in the day at the weekends?
It is not affecting her sleep at night, she still goes from about 8:00 until I wake her in the morning about 6:30 (later on the weekends).
She naps at the CM for about an hour / hour and a half, but on the weekend she can do four hours and is really groggy / miserable if we wake her up.
At what age should she not be having such long naps?
She is two yrs five months (nearly)

Every child's different, maybe she needs this much sleep. If she has always been like this then I would not worry. You could try to wake her 20minutes earlier and see what happens, do the same the next day, then 40 minutes the next ect to try and wean her off the nap but she should grown out of this herself.

She's always been a good sleeper, but her nap times are increasing. She used to either have 2 x 1 hr naps or 1 2hr nap, not we're steering up to 4 hours, at the moment, typically 3.5hrs but she's really groggy and tired for another half hour afterwards.

Is she more active then she used to be when she's awake?

you are so lucky.

Avenanap - she is very active during the day, she is always on the go, likes to run everywhere and we tend to make her walk most of the time as she isn't keen on the pram.

Moodlesoup - I am lucky (though would love to get her to sleep at night in her own bed rather than mine, but that is another story) but it seems unusal to me for her to have nearly four hours!

so during the week she is getting a maximum of about 12 hours sleep in a 24 hour period. Many children need 13 -14 hours sleep (12 hours at night; 1-2 hours nap in the day).

It simply sounds like your dd is catching up on sleep at the weekends, having been at the child minders all week, and I think this is perfectly normal.

If you want to try and change this, I would put her to bed at 7pm every night.

we start the bedtime routine at 7:00. It used to be that we would take her straight to bed at seven, and she'd be asleep by about half past. But when DH changed jobs, we changed her routine slightly, he gets home around 6:45 and takes her in the bath at seven, so she's in bed by seven thirty and asleep by about eight iyswim.

Will talk to DH re changing her so she is sleeping earlier.

you don't have to change anything, unless you feel as though it's a problem.