At Linköpings Karlsson was known as Maria "Mia" Karlsson, due to the presence of younger team–mate and namesake Maria "Kalle" Karlsson. Both left the club after the 2010 Damallsvenskan season. The elder Karlsson was particularly well thought of by Linköpings as she had joined in 2000, when the club played outside the top division and were known as Kenty DFF.
She subsequently played for local club BK Tinnis when her police training allowed. In 2013 she was dual–signed to Växjö FF.