My 1 yr old just doesn't just doesn't drink from bottle with straw, she still uses tumbler..how can i train her to use straw bottles?

I saw a mom sharing an awesome method to train her baby to drink from straw at 7 months old! 1) Cut a typical clear straw into half so that you can see the liquid in it. 2) Hold some water/milk in a straw and let it flow passively into your baby's mouth. This allow your baby to learn that that liquid come out from a straw 3) Hold some water/milk in a straw horizontally so that your baby can suck it out but it's easier than when the straw is vertical. 4) Repeat until your baby learns that sucking the straw gets the water/milk out. I'm planning to train my boy who is now 6 months old by using this method too.