You are a familiar, familial based love. Long term, well connected and stable.
She could well be mixing up love, lust and nre. I do believe that happens, although it is rarely talked about. lust and nre are easy waves to ride. Seriously, what does it involved but some time and body parts.
Your love is work, represents work and is tonnes of time. You have how many years with her? and how much time has she has with her new lover?
Quath is right, nre lasts about 6 months. Give it time and have patience. I believed the love I felt for our ex was the most intense ever. Once my head cleared and my hormones returned to normal, it was all about the same as I felt with my wife and the gf before that. In the moment, it is like a drug high