Hello,
We are providing health insurances dedicated to expatriates in Poland, but unfortunately, they are not valid for locals. So, your polish girlfriend will not be covered since she is not "expatriate" in Poland. I would suggest you to give a call to a local insurance and ask for someone who speaks english to help you. Don't try to use the Google translator, since the information that are usually requested should be answered very accurately.
You would not want to pay an insurance just to find out later that you are were covered for your needs.
If you need any more information, please write and we will be happy to help you.