Thank you for your query.
Do not panic.
I think this might be a case of indigestion
and mild gastritis
If it is associated with loose motion
then probably she is suffering from gastroenteritis
Give her the milk she usually tolerates.Give her a mild antiemetic drops if she vomits again.
Please consult a specialist if she worsens.
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing your child a speedy recovery.
Have a nice day.