My mother in law have a green card and been out of the US for one yr and seven month because she was sick and getting hospitalized overseas now being better she is planning in coming to the US. Is she going to have a problems getting into the US

Yes. She cannot just use her green card to enter the U.S. anymore. If she didn't apply for a re-entry permit before she left the U.S. (I'm assuming she hasn't), she needs to apply for an SB-1 returning resident visa.