Friend with no money getting married

I have a friend who is broke. They plan on a very basic courthouse wedding and have set the date. She is really depressed and sad because she has always dreamed of having a party. But, she also has a kid and wants to be married as soon as possible. So they won't wait to save.

I suggested doing something and she got so excited. She's thinking little because of money but I know she had said she has always dreamed of the cake and the dance (before she knew they would be getting married so soon).

I don't have a lot of extra money..

This is an idea that I would not start until confirming with her. I can rent a school gym that looks ok for $25 per hour + $150dp for that night of her wedding.

I'd skip wine and drinks since that's fairly expensive.

There's still time for me to order a few decorations from china (I have a friend who did her entire wedding with stuff straight from china).

Then I could get the rest from the dollarstore.

I have a friend who would dj and a friend who's band is fairly good and would be willing to play for free.

I can organize a potluck style dinner..

And I can print off invitations to it.

Do you think if she likes the idea it would be wrong to mention the cost to her grandma and grandpa? They have a good business and he makes a lot with it. And I know them from a few little parties.

Otherwise it's like $600 oop probably and tbh that's a lot for me right now.. I'd be happy paying half or something like that..

I'm totally getting ahead of myself.