You’re absolutely right! Being aware is the first step. Thank you so much for your feedback. It is very hard showing equal interests in equal proportions. I think spending time with them individually has really made a difference in how they feel. They appreciate that special bonding time that is set aside just for them.

I love this:

they are different people and respond differently, so while I try to treat them equally I don't treat them the same.

That makes great sense and this pertains to my situation too.