I thought at first my Yum Yum was part siamese but she is a Ragdoll I believe.
Yes, Yum Yum is a Lilac Point Ragdoll. I am sure of it. Your cats are very beautiful. I love any cat that is Siamese. The Ragdoll and the Birman are both part Siamese. If you want some great info on the Ragdoll and the Birman here are some very good sites!

Birman...
http://www.birman.org/

Ragdoll...
http://www.ragdoll-cats.com/

Have Fun!!