Babbling question


My daughter can string vowels together.. can say babababa mamamana, dada also she can string diff vowels together like Ratata, papatata and stuff.. but she doesn't babble all day... she makes a lot of noise... but it's mostly sshhh and aiiiyeee... babbling is sometimes during the day... I have heard people say babies babble all day... but mine doesn't... is it normal? She is 8.5 months old