There appears to be no major mainstream film titled "Lady Sonia" released in 2021 that features conventional romantic storylines. It is possible you are referring to one of the following works with similar names or themes:

: Critics have noted the inclusion of a "fluffy love story" as a framing device, though many felt it contrasted poorly with the film's harsh, realistic portrayal of suffering.

: It is highly praised for Mrunal Thakur's performance but criticized for its "Western savior syndrome" in the climax and for packaging sexual violence with mainstream entertainment tropes. 2. The Loneliness of Sonia and Sunny (2025/2026 Novel)

: The story explores the "fragile love" between Sonia , an aspiring novelist, and Sunny , a journalist.

: The film is a brutal drama about human trafficking rather than a romance. It follows Sonia (Mrunal Thakur), a village girl who travels to Mumbai to rescue her sister Preeti , only to be trapped in the sex trade herself.