Your mom doesn't have to be there; you just have to say you want to talk to the doctors alone if they don't do that themselves. You're an adult so it is your situation. The only time I've been admitted to psych through the psych ER I don't think they would have let anyone in with me until they had asked questions, just because for a few minutes there were several people taking turns getting information from me and then I had to change into a gown and pj pants (just required in the ER; you wear regular clothes in the unit) and there just wasn't space for anyone else until I was settled.