@Amanda1775 If you list for 6, this is going to happen again and again.
Instead of listing for 6, and explaining the age limitation in your ad, I would do the opposite- list for 4 and mention in your description that you can accommodate 2 more if they are 14 years of age or under.
There is no red flag as far as a request coming in at 2am. Take a look at when the request was actually sent. There is often a lag for me in when the Request comes through and when it was sent. I often get notifications of a message at 3am, but when I look at when the guest sent it, they sent it at 9pm.
Also I have had several guests who showed as members for several years who had no reviews. In all of those cases, there was an innocent and reasonable explanation for that, and they all turned out to be great guests. You can always ask about it, too. "I see you have had an Airbnb account for 2 years, but no reviews yet. I'm curious as to why that is- did you join to take a trip and then didn't, or ?"