Her father was an activist of the co-operative movement and a Polish legionnaire during World War I, who was considered a "dangerous element" by the Nazis and murdered at Auschwitz after he was denounced by a colleague of Belarusian origin.

Along with her mother and siblings, she survived the Warsaw Uprising, and was sent to the transit camp in Pruszków.

During her studies, she belonged to the socialist Union of Polish Youth, but as she said, "it is not true, as some are trying to insinuate that I managed the ZMP.

She participated in organizing patriotic concerts and the distribution of underground publications.

In the Polish parliamentary elections in 2011, Łaniewska was a nonpartisan candidate to the Senate on behalf of the Law and Justice party in Warsaw.