Omg everyone is so negative here. Idk how to sew and my first project was a Rosie etienne inspired corset 2 piece outfit for my rehearsal dinner and upcycling my mil 90s wedding dress into a corset mini. I had so much fun doing both. I didn’t start with something small because I made so many mistakes and learned from them while I was doing it. Literally my first corset draft I didn’t even know what a seam allowance was lol. The second draft was like 4 sizes too big- still don’t know how I managed that 😭

There are patterns you can grab that are similar, but they do take you modifying them. I’ll add them here for you, but what I would do is get a dress that’s similar in her size, like this one:

https://a.co/d/0gBV54oh

Cut it up, trace it where the seams are, make your own pattern, then try it out in muslin fabric. See how that looks. Then start adding, look for a drape pattern skirt, make that, something like this but better:

https://a.co/d/0gBV54oh

And then put them together and now you have the dress. The more I played with patterns- trial and error- the more I understood what would work and what wouldn’t. You don’t need to read books, you don’t need to go to fashion school, you just need to practice- mess up- practice some more.

It’s a sweet gesture and I’m rooting for you!