Yep, I agree with Astrid. If I'm feeling overwhelmed I put DDs in childcare for an extra day. I find I get so much more done on my 'bonus' days

It's not unusual for my DD2 to go to sleep REALLY late. To get her to sleep at a reasonable time, I have to make sure she gets tons of physical exercise AND not let her have a nap. Are they sleeping at childcare? I'm not sure what your girls are like but even after childcare all day, DD2 often won't go to sleep very easily. She just doesn't expend much physical energy. She potters. She will sit in the sandpit and play for half an hour. Compared to DD1 who in the same half hour at her age would have done 50 laps of the playground on the bike, been down the slide etc etc. And been asleep by 7.30pm. Oh, those were the days

So if you're doing the obvious things like making sure they have a regular dinner, bath, bed, story routine, then I'd cut out the nap at childcare (if they're having one) and see if there's any way of upping their physical activity.