Post-funeral: Not everyone's invited to the restaurant, so what do you say to them so there are no hurt feelings?

Today is my mom’s funeral. After the funeral, we’re going to the cemetery and then to lunch (late lunch/early dinner).

My family planned the lunch, and it’s at an expensive restaurant (probably between the food and the wine, it will be $100 per person, if I were to guess). I’ve been told that not everyone is invited, and they want to keep it to those who knew my mom, close friends and family. With those, there will probably be 20 to 30 people.

I have friends that are coming that might be expected to be invited. A friend asked me if all who go to the cemetery are invited to lunch, and she told me that in the Italian culture, everyone who goes to the church and then cemetery is invited to “break bread” with the family and go to the lunch. We’re not Italian, but she was giving me an example of how some cultures do it. She said she wants to go to support me and I guess she was asking because she’s trying to plan her day and free time if she’s going to have it.

Since this is not how my family is choosing to do it, and since I’m not the one paying, it’s not up to me. If it were up to me, I’d probably choose a less expensive restaurant and make it open to all, but it’s not my choice.

What is a way to thank people for coming and then let them know we’re parting and they’re not invited?

I feel like it’s awkward. I don’t want anybody hurt or insulted or confused.