I'm going to step up and be the champion for the maid cafe here.
There is a common misconception about what a maid cafe is about. It's not something raunchy by any means, nor is it what you would call a weeaboo buffet.
Maid cafes are a sort of dinner and show and are VERY family friendly. Having spent my time in Japan and visited a couple maid cafes stateside as well, if done right, anyone of any age should easily be able to enjoy themselves in this sort of situation.
Allow me to give an example of a maid cafe I made time for at a recent comic con. About twelve of us had tickets for the time slot and about five girls in maid's costumes sat us down between two tables. While they took drinks, everyone introduced themselves, and we looked over the small menu. These menus are usually made by the maids themselves; in fact, that's a key element, that it's food that the maids have cooked themselves. They took food orders, and while we ate, they all put on a very silly and fun dance to music for us all. After that, we played a couple games of table against table charades with our maids partaking with us. We were all behaving as good friends. It was scarce that I could believe that an hour passed in such fashion and fun.
Truly, this is a very family friendly activity, so long as whatever program they posit is geared that way.