Mrs. Doubtfire Doc Would Be A Joy, Love To Be Involved, Says Lisa Jakub

Yes, dear ... it really has been 30 years since Mrs. Doubtfire made herself comfortable in our homes ... and one of its stars, Lisa Jakub, is crossing her fingers hoping that talks of a doc will break cover.

Lisa was only 14 years old when she portrayed Lydia -- the eldest of the three Hillard kiddos -- in the comedy alongside the late and great Robin Williams ... who played a recent divorcee morphing into an eccentric British nanny to spend more time with his kids.

And Lisa now tells TMZ that after catching wind of the flick's director, Chris Columbus, spilling the tea on a potential doc celebrating the 1993 classic, she'd be totally down to share her experiences on set and contribute some nostalgic joy if invited to be involved.

As for now, Lisa hasn't heard directly from Chris himself -- adding to us she only found out about the budding doc when a pal texted her about it ... but she's keen on taking a trip down memory lane -- especially as the movie is meaningful for so many people.

If the doc goes ahead, there'll be plenty of unseen footage to use -- nearly 2 million feet worth -- as Lisa says cameras rolled more than usual... due to Robin's hilarious knack for improv and her inability to keep a straight face.

She also reflects on Robin's life lessons, telling us he encouraged her to be present in the moment rather than waiting for her turn to talk -- advice that's bettered her job as a certified yoga teacher and mental health advocate.

This comes after Dir. Chris discussed plans for the potential doc ... telling Business Insider earlier this week that he's got his eye on 972 boxes of footage left on the cutting room floor ... hoping it'll show the "special" and "magical" way Robin went about his work.