Katia Aveiro, a musician, is said to owe the money for the flat she owns in Setubal, near Lisbon.
Reports from Portugal claim the 40, year, old was taken to court after neighbours tried and failed to track her down to pay her bills.
The debt was supposed to cover things like cleaning and pool maintenance which was a fixed charge between the period of 2015 and 2016.
This is not the only debt she has outstanding; it is believed she also owes on another apartment she shared with her former lover Antonio Camelier.
Katia is not stranger to controversy; she drew the ire of her brother Cristiano when Claudio Coelho claimed he had bedded Aveiro - in her famous brother's houses in both Madrid and Geres, Portugal.
Also Ronaldo was angry when he discovered his sister was romantically linked with Celso Cota, who was sentenced to seven years in prison for drug trafficking.
Did you check out the latest update for my mobile game? It's awesome! How many goals can you score?— Cristiano Ronaldo (@Cristiano) March 14, 2017
Update Now: https://t.co/RX5FZclXci pic.twitter.com/UYrGY97RSa