I think the OP said they had seats, just not together.

Check in

Either counter or gate can do their best to move you around or at least put the girls together. There are three seats showing open now (two are exit row, though) but all is under Airport Control. This is in addition to any blocked seats. Just be at the counter/gate early in case the flight does not fully load and before stand-bys are processed

I have not seen very many groups on the AUA flights especially on a weekday. Most travelers on this route are very amiable and I really do not think you will have an issue.

OP Drop me a PM - I will be there Saturday for a day or so to take care of some matters.