Toddler Speech Development

Hi mommy, I wanted to ask your opinion if my baby is on track on her speech development. She is 17mos old and can talk 7-8 words already with purpose and can understand and do most of what we asks her to do. However my concern is she won't call me "mama". I keep on teaching her but gets nothing to it. She won't tag names on me peru kilala naman nya ako as her mom. Should I need to be concerned on this, mies? Thank you.