Someone that is severely depressed is having anger outbursts. What should I do

My sibling burst into a rage recently but she has been having issues for quite a bit. There is a developmental delay with her but she’s in her mid 20s with the development of a 10 year old.

But this anger thing is new. She tried to hit my other relative when they were trying to calm her down. Then she burst into tears and has isolated herself for the past three days

The anger came back when we offered food. I’m not sure what to do. Should get her psyc evaluated ? Where can I go for this ? What can I do if it’s not getting better. She’s not cooperating