Tyler Perry's lifeline for an elderly woman fighting to hang on to the South Carolina property her family's owned since the Civil War era includes a new home with a swimming pool.

Josephine Wright is the 93-year-old woman duking it out with a developer in Hilton Head and her granddaughter, Charise, tells TMZ ... Tyler got in touch with the family and asked Josephine what she wanted in a new home, and she told him 5 bedrooms plus a pool.

Charise says Tyler agreed and his team sent Josephine the blueprints. But, she says her grandma is very particular and asked for a few minor changes ... and he obliged.

As you can see in the blueprint, obtained by TMZ, there's also a game room, dining room, home office, media room and a big porch.

We're told Tyler is gifting Josephine a modular home ... meaning it will be built off-site and then moved to a separate part of her expansive property, so she won't have to leave the plot of land that's been passed down by her family for generations.

Charise says part of her grandma's current home is built on the section of property that is the subject of a bitter land dispute.

TMZ broke the story ... Tyler's buying the home and construction crews will get to work in a few weeks once all the permits are squared away.

Tyler pledged his support to Josephine back in July after learning of her plight ... and Charise tells us he reached out to the family in late August to get the ball rolling on the new home.

As for Josephine's legal showdown with the developer ... we're told both sides are still in deliberations.

Charise tells TMZ ... "My Grandmother would like to thank all the people all over the world who looked at her and didn't see a little fragile lady but a giant ready to fight to keep what's rightfully hers. She is humbled and so appreciative, God bless."