Upon graduating from the NFTS in the UK, Marianela wrote and directed several short fiction films, including The Look of Happiness and Breaking Out, both premiered at the Cannes Film Festival. As a screenwriter in the UK, Marianela co-wrote Peter and the Wolf (Oscar Winner, 2008), Unmade Beds (Sundance, Berlin, Rotterdam 2009), The Flying Machine (Toronto & 3D Film Festival 2013) and The Magic Piano (New York Film Festival, 2011, and shortlisted for the 2012 Oscars). She also participated in the prestigious Cannes Writing Residency, where she wrote The Other Girl, currently in development. As a documentary filmmaker, she worked for BBC Mundo and co-wrote Once upon a Time in Venezuela, which premiered at Sundance in 2020. She is currently developing several projects for film and television in the creative label Serious Ladies and her own company, Invento Films.