Sebastian studied fine art at Goldsmiths College, the Royal Drawing School, the Slade School of Art, and was a recipient of The Irving Wernick Memorial Scholarship. She has exhibited internationally including at the Ghetto Biennale, Port-au-Prince, Libertine, Los Angeles, Tangent Projects, Barcelona, HBFK Institute, Hamburg, and in London including Somerset House, Auto Italia, and Harlesdon High Street. Recent exhibitions include: The House, IMT Gallery, London; Domestic Flights, Frestonian Gallery, London (2025), The Wicker Arms, Staffordshire St, London (2025), Figurative Impressions, Hurst Gallery, London (2024) and the solo presentation What We May Also Do at Verdurin, London (2024). Sebastian illustrated the The Weeping Hemlock, a book of poems by Reuben Dendinger, published by New American Poetry in 2024, and the cover art for Cursed Images, also by Reuben Dendinger, published by Hyperidean Press in 2023.