Concerns over psychiatric issues regarding adult daughter?

I have an adult daughter, in her early 20's who I STRONGLY believe has a personality disorder. Without going into a lot of detail, her moods are unpredictable and extreme, generally does not care what she says to others or their reactions, regularly needs reurance and believes others are persecuting or 'against' her, etc. (there are many more symptoms). Adding to my concern, my daughter just had a baby. I do not believe that these issues are a result of the pregnancy or postpartum depression/psychosis, as she exibited the same symptoms for a few years prior to becoming pregnant. I am, however, VERY concerned for her and subsequently her daughter. I have tried both tactfully and directly to get her to seek treatment, but she absolutely refuses. Recently, I tried to get her to go to the ER for a minor issue, just so that I could try to pull the nurse aside and explain why I really took her there, in the hopes that they would provide a psych consult. Of course, my daughter refused to go to the ER tho. I'm at my wits end and need any advice that anyone has. My daughter and granddaugter live with me, so at least I can try to keep an eye on them both, but this cant go on indefinitely and I really have no idea what to do! Any suggestions or even legal advice? BTW, I live in AZ (for legal advice). Thank you so much!