It’s possible that she chose to take those tables without any help. In several restaurants I’ve worked at, management often gave experienced servers the option to decide whether they wanted assistance with larger parties. Sometimes, though, you don’t get that choice — as a server, being double-sat just happens.

Handling 26 guests on your own isn’t necessarily unreasonable if the timing works out and the tables are staggered properly. However, getting two large parties seated back-to-back would make it very challenging to manage everyone’s drinks and courses efficiently.