Hello,
My DS did that at 10 months, despite downing bottles previously to that. I didn't worry too much as he was older and ate a good amount of solids - although I did miss the bedtime bottle when we could cuddle and he would stroke my hair while drinking :(
It then occurred me that my brother and I are both lactose in tolerant - not massively I can eat things like parmesan and butter i.e, stuff relatively low in lactose but I can't do milk at all. My mother then told me that we both weaned ourselves off bottles roughly around 8 to 10 months.
So I just didn't give any milk and kept an eye on whether he would react with cheese/butter/cream/yoghurt ect, which he didn't.
About 6 months ago (when he was 2) he decided he wanted to drink milk as one of his little friends did, so I gave him some and I then realised that whenever he had milk he'd have explosive diarrhea for the next 2 days, so I figured he really couldn't do milk and we switched to oatmilk, which he loves.
You could get your little one tested, speak to your GP as if she is intolerant or allergic you should be able to get a replacement formula on prescription.
I haven't bothered as mine doesn't need to drink milk, he just wants to be like the others.
Obviously, as others said it could also be a myriad of other things like teething or wanting to feed herself..
Good luck