Age of consent is 14 in quite a few European countries. It's not that uncommon.
The problem is that wherever you set the age, you're always going to be simultaneously criminalising some kids who really aren't doing anything wrong, and legalising some abuse by adults.
If you set it very low (say 12) to avoid the former you increase the risk of the latter, if you set it very high (say 18) to avoid the latter you increase the former.
The answer surely lies in intelligent enforcement - don't prosecute technical breaches by consenting minors, but be very zealous in pursuing abusive relationships at ANY age.