David Patrick Jan 28, 2022:

If this is a stand-alone sentence it's very unlikely to refer to conversation or catching up on gossip. There would need to be more detail like, "They hadn't seen the Brewer family in ages but caught up with them over the bank holiday weekend. Also, "A party consisting of A, B and C" suggests this refers to physically reaching / arriving at the same point.

Port City Jan 28, 2022:

文脈は？ Catch up with の意味はひとつではないので、もう少し文脈が分からないと訳は提案しかねます。文脈によって、追いかけて「追いつく」とか、3人が彼らと「話す」とか、色々と考えられます。ただ、talk with の意味で catch up with を使うと、その前の a party consisting of ... と register (表現の固さ、やわらかさ）が合わないように思います。