i think هل لديك مشروب يا سامية makes more sense
Why? As a native speaker, I'm not aware of any semantic difference between لدى and عند.
I have learned that لدى is for people and عند is for things.
One more question : if you are a native speaker, why are you learning Arabic again? Doesn't make sense if you ask me.
Anyway, hope my comment helps you. :)
How will we translate 'do samia has a drink?'
هل عند سامية مشروب؟