There is a 16yo girl that likes my 11yo brother. Tell me that there's something wrong with this. If these 16yos can't find anybody their age, then they need to wait until they're older. For the 16yo male, I would not mind it, nor would I care if he was 21 and my sister was 18. I am saying 'no' to this because my sister lacks lots of maturity and basic knowledge. The 16yo female and my 11yo brother is a big no.
At this point, these teenagers need a "sit down and talk" about which age group is okay to date and which ones are not, because this is just ridiculous.