Ima be serious. Yes, it is a real problem dating someone that’s half your age. You’re not going to have much in common. That being said, you’re interpreting those looks that way because you’re experiencing regret for not being someone who could be in a relationship with her. The fact you’re gauging her against nieces and nephews is less about you actually thinking about her in a romantic way and more about you looking at her as a reflection of what you think you could have been 20 years ago. You’re using a (probably) innocent glance to beat yourself up.