The person you got her from should have first and foremost, been upfront and honest about it...she does look like she's mixed with something...For someone to lie about it though, doesn't sound to me that she's an honest or reputable breeder(if that's what she calls herself)...BUT, she is soooooooo cute! I would fall in love with her in a minute!!
Did she own other dogs that you know of?
Welcome to YT!