4 year old question...?

My little girl is 4 years old,ever since she was a baby she had reflux and had alot projectile vomits.It settled as she got older but she is very sensitive to stuff like if she dont like the smell of something she will want to vomit,or if she sees hospital stuff on tv she wants to vomit.....even one time she didnt like the look or smell of someone and wanted to vomit this is driving me nuts and it gets embaring cause if we go to dinner and she does not like the taste of something she will vomit also please help...