3 year old - reflux??

[Nonononomaybe]

My DD is 3, nearly 4 and for the last 2 or 3 weeks I’ve noticed her burping a lot (albeit quietly) and I think she is occasionally bringing stuff up into her mouth and has a dry cough/ sniffs afterwards. It seems to be worse in the evening, but perhaps it’s just more noticeable when things are quiet.
She hasn’t complained about it and if I ask her she says it’s just a ‘rude noise’ and that she can’t help it.
She’s never had any problems with digestion, was tongue tied as a baby but that was rectified in the first month or so.
She has days where she eats noticeably less than others and has never had a huge appetite but is a healthy weight for her height etc.
I have a GP telephone appointment for next week but does anyone know could this be reflux? Can it develop at this sort of age?
Any help or advice appreciated!

DD is 2.5 and still has occasional reflux, usually a burp and a mini sick or swallow. Though she had silent reflux & colic as a newborn and was very gaggy between 6-18 months so the random sickness has been slowly decreasing in frequency rather than a new development. However the reflux was very subtle, easily missed in the baby-early toddler years. If it hadn't been for lockdown and being with her 24-7 I probably wouldn't have realised at all.

I do however notice phases where it tends to be more frequent and then I try to adjust her diet to more bland foods. Just like with adults, I think foods that are too acidic, sugary or fatty tend to make it worse.

Other than this DD also has no problems with her appetite, digestion, no allergies or food intolerances. She has a very low weight percentile but our doctor isn't too concerned as I'm also low BMI and have been my entire life.