Help! What is this dog?

by Debby Mercer
(La Habra, CA)

I bought Kevin from a family that said she was a Beagle (and a boy). Turns out Kevin is a girl and a mix of something. I think she is part Jack Russell but most say Chihuahua. She is now 4 1/2 months old. I have attached 2 pictures. One from September and one from a few days ago. Her ears were flopped over but now they stand straight up...which does make her look like a Chihuahua. She has all the characteristics of a Jack. Maybe someone can help identify her breed. I'm seriously considering a DNA test. Thanks!