My 7 month old will only take the orthodontic latex nipples.?

The only problem is that she only likes the worn in ones. I bought new nipples and they are hard and not stretched out. I don't know what to do. She does not like the normal silicon or latex nipples. She just chews on them.My 7 month old will only take the orthodontic latex nipples.?
My son will only take evenflo comfi nipples so I'm not much help sorry! Just give her what she likes! Good Luck!

lakers