It is reasonable to ask them to change their habits, definitely. It annoys you, and there is a solution.
Saying that, the perfect solution requires the kids to stop running around in the flat, or find a way where you can't hear it, and stop screaming going down the stairs, or again, find a way to stop the noise.
Stopping them running round the flat.
Not going to happen 100%.
Definitely talk with the mother. Invite her for a coffee/whatever, and then mention your headaches, hope that the mother has also had enough of the running around, and uses you as an excuse to stop them. It's a possibility. Sympathetic angle. Might cut down a bit more of the noise.
Suggesting to go out more ( in a nice way ) would, if accepted, cut down on the running around. I don't know you, I don't know her. Good luck with finding a 'nice' way to say that, but if you can get that into her head then you're half way there.
When we used to stay at my Grandparents appartment in Zürich in the 60s and early 70s we HAD to be quiet, otherwise Frau C......... ( no names, she's probably dead by now anyway ) would come up and shout and scream, so we were always sent out to the playground or the kiosk at regular intervals throughout the day.
We were also NOT allowed to run around, but times have changed, sadly.
Anyway, so, try the friendly approach with her first, and if it goes well then you are sorted, and have a 'friend'.
Then perhaps suggest a runner ( carpet ) in the corridor, they are not expensive, or suggest they run around in slippers ( maybe buy them a pair each, very cheap in Dosenbach, and they always have funny and pretty varieties ), this would also be reasonable, and if implemented, works a treat.
These are the reasonable alternatives. Cheap, and could bring about something positive, a new friend.
More expensive options for sound-proofing in your appartment.
Forget it. Nothing works. You can stick whatever you like on your ceiling, it will not work. Acoustic ceilings, all that stuff. Rubbish. Just in case you were thinking of getting someone in. Carpets and slippers DO work.
If it doesn't look that positive, then she will never be a 'friend', so then approach it in a more aggressive way.
Bang on the ceiling, complain to the Verwaltung ( although sadly this will probably not sort anything out, but you might be lucky. It certainly won't hurt, you won't be put on a black list or anything, it is common here )
Lastly, go up on a bad day, after a drink, and just tell her to please be quiet, as you have a headache, and feel a bit 'strange'. Then stare into her eyes for 4 to 5 seconds, laugh hysterically, swish your hair back and jump downstairs landing loudly on every step, before getting back into your flat, slamming the door, and starting up the chain saw.
You will need a chain saw.