回複：ask experts like PJIANG etc B-2 extension for my mother

We tried it 2 years ago(for the same reason, for kids), and got denied. The reason was the same thing, didn't provide detailed plan. I think they are looking for something like travel plans. If you say you are going to visit some places, you need to list all the cities and detailed schedule of your visit. And what you are going to do there.

Wish you good luck.