Of the three of us, she's the only one that ever drinks (when she hangs out with drinkers.)
Many people don't really accept polyamory. My girl introduced the idea to me. She's also the one who asked the younger girl to join us. I was surprised when I let my mom know a small amount of my romantic life & found out she has a bigger problem with my polyamory than my Sadism (the latter of which I won't discuss here).
The younger girl's got high anxiety issues & finds people her own age more overwhelming. I also apparently give very calming hugs... (I managed to wind up with two girls that take anxiety medication.)
She's a sort of person that won't speak up to ensure her opinion is known. Where most people would assume she's having a good time because she's not making any complaints or suggestions, my girl & I specifically ask for her input on things because we know this about her & want her to enjoy things as much as we do. She can be content just doing what makes those around her happy, but enjoyment is better than simply being content.
Between her anxiety, especially around people her own age, & how easy it is for people to accidentally take advantage of her & not notice, I think our relationship is quite good for her.