My mother, Jill Theis, who has died aged 90, was a Liberal, then Lib Dem councillor, who cared deeply about her community in Bexhill-on-Sea, East Sussex, and was instrumental in restoring one of its architectural landmarks.

Born Julia Mason in St Leonards-on-Sea, she was the daughter of Maurice Mason, an eye surgeon in Hastings, and his wife, Henrietta (“Gottie”) (nee Kennedy Jones). Jill attended Roedean school in Brighton. As a teenager during the second world war she would sit on the cliffs overlooking the Channel, watching bombers fly over.

After leaving school she entered the Central School of Speech and Drama, London, then went to New York and worked on Time magazine for a year. She also worked as a park-keeper and in a flower shop.

In 1955 she met Mike Theis, a development planner, in London. They married in 1956 and made their home in Catsfield, East Sussex. They had five children.

Jill was well known for her baking – in particular, her brownies and brown bread. In the early 1970s she set up a business with her neighbour called Henley Down Bread, selling fresh bread, followed by bread kits – a baking tin, instructions and all you needed to make your first brown loaf. The kits were a great success and were sold in Harrods.

Facebook Twitter Pinterest Jill Theis at the De La Warr Pavilion, Bexhill-on-Sea; she was a founder of the trust that helped restore the pavilion

In the mid 70s Jill and Mike went to Nigeria, where Mike worked as an urban planner. On their return in the late 70s, Jill’s interest in politics was ignited by a visit from Richard Moore, a Liberal party campaigner. In 1983 she was elected as a Liberal member of Rother district council. She proudly represented her local community on the council until 1999, working tirelessly to defend local services.

Through her work on the council, Jill became interested in the De La Warr Pavilion, an Erich Mendelsohn building in Bexhill-on-Sea that she had visited when it opened in 1935. The council was struggling to run it, and it required restoration and good management. Jill formed a small group, the Pavilion Trust, which set about restoring the pavilion accurately and creating an arts programme to attract new audiences. It reopened in 2005 after 18 months’ work.

In 2004 Jill was appointed MBE for her services to local architecture. She later organised a competition to design a new bandstand, which was built and opened in 2009 to much acclaim. She stayed involved with the pavilion, attending events and supporting its management. She attended its 80th birthday celebrations in 2015.

Jill is survived by her husband, by four children, Tooza, Patrick, Martha and me, by 11 grandchildren and two great-grandchildren. Another child, Senden, died in 1974.