Frank Sinatra's daughter is weighing in on Martin Scorsese's plans to turn the singer's life into a film -- and from the sounds of it ... she's more than fine with the project.

ICYMI ... Martin is planning to make a biopic about Ol' Blue Eyes -- with Leonardo DiCaprio potentially playing the famed crooner. According to reports, Tina Sinatra, Frank's daughter who controls her father's estate, hasn't yet given her blessing for the upcoming movie.

However, Tina talked to us ... and when we asked her directly about her thoughts on Scorsese's plans -- ones he's circled for many years now -- she sounded positive.

Tina tells us ... "Marty and I have been dance partners for a long time and not once has he stepped on my toes!" She added, "Always here for Marty."

Of course, that sounds like a cosign -- but when we tried clarifying whether she was for sure onboard with the direction MS plans to take it in ... Tina wouldn't give us a straight answer.

Still, the responses she provided are telling in and of themselves -- especially since there've been issues with her and Scorsese before when it comes to giving her dad's life the movie treatment. In 2014, Tina had reportedly expressed displeasure with Marty's vision ... namely, making a hard-hitting biopic getting into all ugly elements of Frank's legacy.

Scorsese had given up on the project in 2017, saying the family wouldn't let him do it -- but now that he is, in fact, doing it ... it would appear the fam, including Tina, has signed off.