How can I merge 2 conversations in Messages with the same people, just a different order?

I have a conversation with "Mom & Sisters" that lists 3 people. Somewhere along the way, my mom (probably) started a new conversation with the same people but in a different order. Same contact info, just different order. Now we have 2 separate conversations and sometimes she will respond to one and not the other.

Is there a way to merge these?