have a look at this link on the BB main page. https://www.bellybelly.com.au/baby/reflux-in-babies

I have known a few babies to not agree with S26. I'm aware every baby is different but if you are thinking of changing formula, I would do it early on rather than leave it too long. Change it now and see if it makes a difference. Also, after a feed, maybe keep her upright for an hour or so and see if that makes a difference. Another suggestion is raising her cot mattress.
HTH