Dear Silvia,
I have also heard good things about Katica Tanya. I've had good luck with several hotels in this chain
http://www.hunguesthotels.hu/en/ and you can check each one for children's pools and activities and babysitting.
My absolute favorite is just over the border in Austria,
http://www.sonnenpark.at/index.php?id=352&L=1 where there are stroller paths, free stroller and bike rental, rooms come with breastfeeding pillow (!), bunk beds for larger kids, potty helpers and stools in the bathroom. There are kids' activities all day every day indoors and outdoors, not to mention the HUGE indoor water park that the hotel is attached to (free entry with room reservation). They even give you a babyphone (monitor) so you can go sit in the jacuzzi and run back if your child cries...
If you find that too expensive, there is a "pension" next door to the water park that is also charming and kid-friendly,
http://www.apfelhof.at/ where they make all their own fruit juices (and wines of course) and serve homemade breads and cheeses, both in the breakfast room and their own little restaurant.
I hope you find, and have, a nice vacation!