I think the lunching situation has been resolved - basically, it seems like I will be able to eat lunch with the other two new girls each day, although one of them is only over in our building temporarily to be trained, and will be permanently working about five minutes' drive from us. We've decided to go out to a Mexican place that they both like and I haven't been to - but we have all agreed that spending money on lunch is wasteful. One of them actually said, you know, if you spend $25 a week on lunch, that's $100 a month! (Which is of course something regularly said in the PF community, but I would have felt like a big dork saying it myself. =)
The three of us have also had long conversations at lunch about how people spend their money wastefully, and how people try to convince us to spend more money. (Both girls have significant savings despite holding essentially student-wage jobs previously.) They also both described themselves as penny pinchers. So I feel like I have found financial kindred spirits and I am quite satisfied.
They also serve as a kind of financial conscience - I know that I will feel wasteful if I bring in restaurant leftovers for lunch three times in one week because then they will know I ate out three times for dinner. ;) So that's going to keep me in line there too!
I did feel kind of bad on Friday though because my mentor lady didn't have anyone to go with because the lady we usually ate with is not there on Fridays, and I was going off to eat with the other girls. She did eventually find someone who would go with her, but if I hadn't said I was going with the other girls then it would have been just the two of us and she could have gone to lunch when she wanted, instead of waiting for someone else to come back to go with her.