[Help] Puppy has 2 rows of teeth!

I have a toy breed Shih Tzu that just turned 4 months. And this morning when I was playing with her, I noticed she had 2 teeth in 2 rows! The rest of the teeth are okay, but the front tooth had 2 rows!Is this very normal and will the adult tooth eventually fall off? If not what should I do? via /r/dogs http://ift.tt/2sGsWjf