Why is DD vomitting

[KikiShack]

DD is 21 weeks, EBF, and likes her food! Born at 8.12, she has piled weight on and currently weighs nearly 23lbs.
I have / had? oversupply, but as she's bigger now she can cope and rarely pulls off at the beginning.
DD vomits about once every week or two. Always at night during her huge feed to sleep. I can only assume this is because she's stuffed herself too full.
I don't think it is because of wind, I don't burp her much as she doesn't normally need it, and she is normally fine. I can't think why it happens, and what I can do to stop it happening.
Anyone got any ideas? TIA.

bump

Not sure if it's the same thing but my DD would sometimes overfill herself and we would get the excess back - not quite a vomit, just the 'overflow'. She's still a boob monster now at 11 months..

I think sometimes they just do! Trapped air bubble, cough, milk down the wrong way... Unless it happens frequently or really upsets her, I wouldn't worry about it. HTH