Hi Evy! Your babies are adorable. As to being full bred chihuahuas, I don't believe they are from the looks of them. Looks like they have some lab in them. Since you had chihuahuas before, you know they have longer, pointier snouts, and large upright ears. (I realize dog's ears don't stand up completely until they are 6+ months old), but your girls don't look like full chihuahuas. One thing IS for sure....they are 100% pure lovable pups! That said....THEY ARE SO CUTE!!!! I love them!!!!
I had chihuahuas at one time (3), but 2 were long hairs and weighed about 2 lbs., the other looked like a min pin and weighed about 10 lbs. All lived to be 18+ years old. I now have a German Shepherd and my girl weighs in at a hefty 110 pounds. She's 7 on Halloween and loves me to pieces.
Good luck with your beautiful girls! Hope the training is going well.
Anita