No One takes me seriously because of my voice?

Hehro everyone who is reading this Lately, I've been feeling people don't take me seriously because of my voice I am a fifteen year old girl and I sound like a very small child? What I mean by people not taking me seriously is for example, my friends are having a conversation dealing with important matters and I'll sometimes (when I'm feeling brave, which isn't very often? join in and when I do speak they all laugh and say "HAHA, that's cute " or "oh my god you sounded JUST LIKE my seven year old sister haha " and they always dismiss what I say as unimportant and trivial I think some of you probably think Im exaggerating?^_^ i have a lot of guy friends and we usually makes videos... and usually they are reaaaaly funny and my friends will show them to other people and the other people that don't know how old I truly am will tell them:"Why are you cursing and talking about inappropriate stuff in front of that little girl?" Or "why are you flirting with her that girl sounds like five holy shit!" The struggle... is real Umm, also, I'm scared that when I grow up, I won't get any jobs because people won't take me seriously or just get downsized at work I usually get asked about my voice a lot... and one time, my chem teacher asked why I spoke as If I was crying Please, may I have some advice? u_u Thank you very much!
No One takes me seriously because of my voice?
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