Hiya I hope someone can help;

My nearly 15 month old is saying a few words (when she wants) mumma, dada, ted and does seem to say a few words like hi, six, woof woof but some words are whispered? Mumma dada she says loudly and babbles loudly but if we ask her to say something or teaching her a new word she’ll whisper it or she’ll get excited to see ted the dog but whisper ted?! Everything on gooogle leads to autism but we’re confident she’s not autistic (has eye contact, smiles, sociable, plays with others etc) so no problems there just whispering wondering if anyone knows of anything similar? Thank you