or he can just apply here!
He'd need to be paying ZUS though, surely?
You can get one for your daughter and she will be entitled to medical care in Poland as if it were in the UK.
Not quite - it's only really for treatment at the short term level. If she was to get seriously long term sick (but not to the point of needing to be in hospital), there could be problems - the EHIC isn't intended to be used for that kind of thing (your home country is).
Using the EHIC is fine for casual visits to the doctor and emergency care, but not for long term care. On the good side - if either the original poster or his wife pays ZUS, then the whole family is covered.