Here's some information on Ivy Improta, which comes from a 2003 article by Bruce Gilman about the pianist's grandson, musician Gabriel Improta:
Ivy Improta was a child prodigy who Villa-Lobos brought to Rio de Janeiro from the interior São Paulo for studies with Tomás Teran. She worked with Villa-Lobos throughout her career and became recognized as the classical pianist who toured extensively, unveiling Brazilian classical music both solo and with orchestras. Tomás Teran introduced her to Eurico Nogueira França, a pianist, teacher of music history, and music journalist for Correio da Manhã, Jornal do Brasil, and O Estado de S. Paulo. He was a close friend of Villa-Lobos, and together they worked to establish the Academia Brasileira de Música (Brazilian Music Academy). When Ivy was 20 years old, they were married; their best man was Villa-Lobos.Teran was a close friend of Villa's, and the composer dedicated many great works to him. By the way, he was one of Tom Jobim's teachers.
I've never seen any Villa-Lobos recordings by Ivy Improta, which is a shame. She played the piano in the premiere of the Fantasia Concertante for piano, clarinet, and bassoon (a work which was dedicated to the pianist Eugene List.) This seems to be the only picture of her on the web: