The nearest hotel I've found that corresponds to presented needs would be Hotel Vestina in Wisła.
The hotel staff will provide assistance in organizing:
- professional nannies
- animation programs for children of all ages
- sport and recreation programs for older children
- the purchase of cosmetic products for children, porridges, juices, etc.
hotel-wisla.pl/dla-dzieci/udogodnienia/
So it seems that they don't hire their own nannies, and just help only with 'organizing' them. Very few hotels with baby care in Poland.